MAINTAIN BLOOD CELL COUNTERS - Laboratory equipment.docx

Laboratory equipment

1. MAINTAIN BLOOD CELL COUNTERS
A blood cell counter, also known as a hematology analyzer, is an essential tool in medical
laboratories used for analyzing blood samples and providing critical diagnostic information. Its
primary functions include counting and categorizing different types of blood cells. Here’s a
breakdown of the key functions:

2. 1. Counting Blood Cells
Blood cell counters perform the basic function of counting the different types of cells in the
blood:
Red Blood Cells (RBCs): The counter measures the concentration of RBCs in a given
volume of blood, which is critical for diagnosing anemia, polycythemia, and other
conditions affecting oxygen transport.
White Blood Cells (WBCs): The total WBC count helps assess immune response, with
high or low counts indicating infections, immune disorders, or blood cancers.
Platelets (PLTs): Platelet count is important for evaluating clotting ability and
diagnosing bleeding disorders or bone marrow diseases.
2. Differential Count of White Blood Cells
Advanced blood cell counters provide a differential count of white blood cells, classifying them
into different types, such as:
Neutrophils: Often elevated in bacterial infections and inflammatory diseases.
Lymphocytes: Associated with viral infections, immune disorders, and certain cancers.
Monocytes: Typically elevated during chronic infections and inflammatory conditions.
Eosinophils: Important in allergic reactions and parasitic infections.
Basophils: Involved in allergic responses and certain blood disorders.
This differential count helps doctors identify specific types of infections, inflammatory diseases,
and hematological malignancies (e.g., leukemia).
3. Measuring Hemoglobin (Hb) Concentration
Blood cell counters often include hemoglobin analysis:
Hemoglobin, the protein that carries oxygen in red blood cells, is measured to evaluate
the blood’s oxygen-carrying capacity.

3. Low hemoglobin levels indicate anemia, while high levels may indicate conditions like
polycythemia.
4. Determining Hematocrit (Hct)
Hematocrit represents the proportion of red blood cells to the total blood volume. Blood cell
counters automatically calculate this by measuring:
Packed Cell Volume (PCV): The proportion of the blood volume occupied by RBCs.
Hematocrit is useful in assessing conditions like dehydration (high Hct) or anemia (low Hct).
5. Calculating Red Blood Cell Indices
Blood cell counters can calculate red blood cell indices, which provide insight into the size and
hemoglobin content of red blood cells:
Mean Corpuscular Volume (MCV): Measures the average size of RBCs. It helps
classify anemia as microcytic, normocytic, or macrocytic.
Mean Corpuscular Hemoglobin (MCH): Reflects the average amount of hemoglobin
per red blood cell.
Mean Corpuscular Hemoglobin Concentration (MCHC): Indicates the average
concentration of hemoglobin in red blood cells.
These indices help in the diagnosis and classification of different types of anemia and other red
blood cell disorders.
6. Measuring Platelet Parameters
Blood cell counters also assess platelet-related metrics, which are essential in evaluating blood
clotting and bone marrow function:
Platelet Count (PLT): Indicates the number of platelets in the blood, which is essential
for diagnosing clotting disorders.

4. Mean Platelet Volume (MPV): Reflects the average size of platelets, which can help in
assessing platelet production and function.
Platelet Distribution Width (PDW): Indicates the variability in platelet size, which can
be useful in diagnosing certain bone marrow disorders.
7. Detecting Abnormal Cells
More advanced blood cell counters can detect the presence of abnormal or immature cells in the
blood:
Immature Granulocytes (IG): Immature white blood cells are typically seen in
infections, sepsis, or bone marrow disorders.
Blast Cells: These immature cells are often found in leukemias and can indicate bone
marrow abnormalities.
Nucleated Red Blood Cells (NRBCs): Normally found in the bone marrow, their
presence in peripheral blood can indicate severe illness or bone marrow disease.
8. Flagging Abnormal Results
Blood cell counters are equipped with software that can "flag" abnormal results or trends,
prompting further manual review or retesting. Examples include:
High or low cell counts: Alerts the operator to values outside normal ranges for RBCs,
WBCs, or platelets.
Unusual cell morphology: Automated analyzers may flag samples with abnormal cell
shapes or sizes, which could indicate diseases like sickle cell anemia, thalassemia, or
cancer.
9. Automated Data Processing
Blood cell counters automatically process and calculate results from blood samples:
Data Storage: Results are stored digitally, allowing easy access for future reference or
comparison.

5. Graphical Data Representation: Some counters provide histograms or scatter plots
showing the distribution and size of blood cells, aiding in the identification of cell
populations and abnormalities.
10. Quality Control
Modern blood cell counters have built-in quality control (QC) systems to ensure the accuracy
and reliability of results:
Internal Calibration: Counters regularly calibrate themselves to ensure that the
measurements are accurate.
QC Samples: Periodic testing with known control samples ensures that the analyzer is
functioning correctly.

6. PARTS OF A BLOOD CELL COUNTER
A blood cell counter, or hematology analyzer, is a sophisticated piece of equipment that is
designed to count and analyze various types of blood cells, such as red blood cells (RBCs), white
blood cells (WBCs), and platelets. It consists of several key parts, each playing a crucial role in
the accurate measurement and analysis of blood components. Below are the main parts of a
typical blood cell counter:
1. Sample Aspiration Unit
Function: This is the part of the analyzer where blood samples are drawn into the
machine. It precisely measures a small volume of blood from the sample tube for
analysis.
Components:
oSyringe or Pipette System: Aspirates the blood sample.
oSample Dilution Chamber: Dilutes the blood sample to appropriate levels for
accurate counting and analysis.
2. Dilution Chamber
Function: Blood samples are often diluted to a specific ratio to facilitate accurate
counting of cells. This is done in a controlled manner to ensure consistent results.
Components:
oDiluent: A solution that dilutes the blood without damaging the cells.
oMixing Mechanism: Ensures that the blood and diluent are properly mixed.
3. Flow Cell / Measurement Chamber
Function: This chamber allows the blood cells to pass through one by one so they can be
analyzed.
Types:
oImpedance-Based Measurement Chambers: Use electrical impedance to detect
and count cells as they pass through a small aperture.

7. oOptical Flow Cells: Use light scattering or laser-based techniques to analyze
cells, as in flow cytometry.
4. Electrodes and Apertures
Function: These are used in impedance-based analyzers to measure the electrical
resistance caused by blood cells passing through a small aperture.
Components:
oElectrodes: Generate an electrical current.
oAperture: A small hole through which blood cells pass, causing changes in
impedance.

8. 5. Optical Detection System
Function: In optical and laser-based analyzers, this system detects cells by analyzing the
light scattered by blood cells as they pass through a laser or light beam.
Components:
oLight Source: Typically, a laser or LED that illuminates the blood cells.
oDetectors: Photodiodes or photomultiplier tubes that detect the scattered light,
which is used to analyze the size and internal structure of the cells.
6. Hydraulic System
Function: This system controls the movement and flow of liquids (blood sample, diluent,
and reagents) within the machine. It manages the aspiration, dilution, and distribution of
the sample through various chambers.
Components:
oPumps: Propel liquids through the system.
oValves: Control the flow and direction of liquids.
oTubing: Connects different parts of the machine to allow fluid movement.

9. 7. Hemoglobin Measuring Unit
Function: In most hematology analyzers, hemoglobin levels are measured separately by
analyzing the optical density of the sample after red blood cells are lysed (broken down)
to release hemoglobin.
Components:
oLysis Reagent: Breaks down red blood cells to release hemoglobin.
oSpectrophotometer: Measures the absorbance of light, which is proportional to
the hemoglobin concentration in the sample.
8. Platelet Counting and Size Measurement System
Function: Blood cell counters typically have a dedicated system to count platelets and
assess their size (mean platelet volume, MPV). This is important for diagnosing clotting
disorders.
Components:
oImpedance Detection (for counting): Uses changes in electrical resistance as
platelets pass through the aperture.
oOptical Detection (for size): Uses light scattering to determine the size
distribution of platelets.
9. Data Processing Unit

10. Function: The data processing unit handles the computation and conversion of raw data
from sensors into meaningful clinical results. It performs functions such as counting,
differentiating, and calculating the different blood cell types and indices.
Components:
oMicroprocessors: Perform the necessary calculations and data analysis.
oMemory Storage: Stores results and historical data.
oSoftware: Used to process data, generate reports, and flag abnormal results.
10. User Interface (Control Panel)
Function: This part allows the user to interact with the blood cell counter, input data, and
configure settings. The interface provides a way to initiate tests, view results, and print
reports.
Components:
oTouchscreen/Keypad: For entering commands and controlling the analyzer.
oDisplay Screen: Shows the test results, histograms, scatter plots, and system
status.
11. Cuvette System

11. Function: Cuvettes are small containers or chambers where the blood sample is analyzed
optically for parameters like hemoglobin. The optical density of the sample in the cuvette
is measured using a spectrophotometer.
12. Calibration and Quality Control System
Function: Ensures the analyzer is working accurately and consistently. Calibration and
quality control (QC) materials are used to regularly test the machine’s performance.
Components:
oCalibration Reagents: Pre-set samples used to adjust the machine’s sensitivity.
oQC Software: Automatically checks whether the machine's performance is within
accepted limits.
13. Waste Management System
Function: Blood samples, diluents, and reagents produce waste, which needs to be
properly disposed of to prevent contamination and maintain a clean system.
Components:
oWaste Collection Chamber: Collects liquid waste from the analysis process.
oWaste Disposal System: Pumps and valves that safely remove waste materials
from the analyzer.

12. 14. Cooling and Ventilation System
Function: Prevents overheating of the machine, especially in high-performance analyzers
that process many samples in a short time.
Components:
oFans: Cool the internal parts of the machine.
oHeat Exchangers: Manage the temperature to avoid malfunction due to heat.
15. Printer (Optional)
Function: Many blood cell counters come with a built-in printer to provide hard copies
of the test results.
TYPES OF BLOOD CELL COUNTERS
Blood cell counters, or hematology analyzers, come in various types, depending on their
technology, capabilities, and the detail of analysis they provide. These devices are used to
measure the concentration and characteristics of different blood cells (e.g., red blood cells, white
blood cells, and platelets). Below are the primary types of blood cell counters:
1. Manual Blood Cell Counters
Manual cell counters are the most basic type and require a technician to manually count cells
under a microscope. These are rarely used in modern laboratories for routine testing but may still
be utilized in specialized situations.
a. Hemocytometer
A specialized microscope slide with a grid that is used to count blood cells in a diluted
sample.
Technicians count cells in a defined area, and the total number is calculated based on the
volume of blood.

13. Advantages: Simple and low cost.
Disadvantages: Time-consuming, labor-intensive, and prone to human error.
2. Automated Blood Cell Counters
Automated hematology analyzers are commonly used in clinical laboratories for routine
complete blood counts (CBCs). They provide faster, more accurate, and higher-throughput
results than manual methods.
a. 3-Part Differential Hematology Analyzers
These analyzers measure the three major types of white blood cells (WBCs) and total
WBC count:
oLymphocytes

14. oMonocytes
oGranulocytes (including neutrophils, eosinophils, and basophils as a group)
They also measure red blood cells, hemoglobin, platelets, and other basic parameters.
Advantages: Cost-effective, suitable for routine blood tests.
Disadvantages: Limited differentiation of WBC subtypes (only three groups).
b. 5-Part Differential Hematology Analyzers
Provide a more detailed analysis of WBCs, differentiating between five specific types:
oNeutrophils
oLymphocytes
oMonocytes
oEosinophils
oBasophils
These analyzers use a combination of impedance and optical methods, such as light
scattering or flow cytometry, for greater precision.
Advantages: More detailed WBC analysis, useful for diagnosing infections, allergies, and blood
cancers.
Disadvantages: More expensive than 3-part analyzers.
METHODS OF OPERATION
Blood cell counters operate using various methods to count, differentiate, and analyze blood
cells. These methods use different physical and optical principles to provide accurate
measurements. Here’s a detailed explanation of the three methods of operation you mentioned:
1. Microscopic Method
The microscopic method involves manually counting blood cells using a microscope, often with
the aid of specialized counting chambers like a hemocytometer. While not commonly used in
modern clinical settings due to advancements in automation, it remains a fundamental approach
for understanding how cell counting works.

15. Process:
Sample Preparation: A blood sample is diluted and placed on a counting grid
(hemocytometer), which has defined areas to help with counting.
Microscopic Examination: A laboratory technician examines the sample under a
microscope, identifies the types of blood cells, and manually counts them within specific
grid areas.
Calculation: The number of cells in the grid is used to calculate the total number of cells
per unit volume of blood.
Advantages:
Useful for detailed examination of cell morphology (size, shape, abnormalities).
Provides flexibility to visually examine rare or abnormal cells that automated machines
may miss.
Disadvantages:
Time-consuming and prone to human error.
Requires skilled technicians.
Limited to small sample sizes and low throughput.
2. Conductivity Method (Impedance/Coulter Principle)
The conductivity method, also known as the Coulter principle, is widely used in automated
hematology analyzers for counting and sizing blood cells. It operates based on electrical
impedance or resistance changes as cells pass through a small aperture.

22. Process:
Aperture and Electrodes: Blood is diluted and passed through a small aperture that is
flanked by two electrodes.
Electrical Resistance: As each cell passes through the aperture, it causes a brief increase
in electrical resistance (impedance). The change in resistance is proportional to the size of
the cell.
Cell Count and Size Measurement: The analyzer counts each electrical pulse
(representing a cell) and measures the size based on the amplitude of the pulse.
Advantages:

23. Fast and automated, capable of processing thousands of cells in a short time.
Provides an accurate count of red blood cells (RBCs), white blood cells (WBCs), and
platelets.
Simple, reliable technology that has been used in hematology for decades.
Disadvantages:
Does not provide detailed information on cell morphology or internal structure.
Limited ability to differentiate white blood cells (used in combination with other methods
for WBC differentials).
3. Dark Field Method
The dark field method is an optical technique where cells are illuminated from the sides rather
than directly from above or below. This creates a dark background, and only the light scattered
by the cells is visible, producing bright images of the cells against a dark backdrop. This method
is commonly used in microscopy but can also be applied in blood cell counters for optical
analysis.
Process:
Side Illumination: Blood cells are illuminated from the sides, and the scattered light is
detected.
Light Scattering: Different types of cells scatter light in characteristic ways depending
on their size, shape, and internal structure.
Cell Counting and Analysis: The scattered light is detected by sensors and analyzed to
count the cells and measure their properties (e.g., size, internal complexity).
Advantages:
Enhances contrast, allowing for better visualization of small, transparent, or poorly
stained cells.
Can provide information about cell morphology and internal structures without the need
for staining.

24. Useful in distinguishing between different types of blood cells based on their light
scattering properties.
Disadvantages:
Limited application in automated blood cell counters compared to impedance and
fluorescence methods.
May not provide as much quantitative data as other methods like flow cytometry.
Comparison of Methods:
Method Principle Advantages Disadvantages
Microscopic
Manual counting using a
microscope and grid
Detailed cell
morphology analysis
Time-consuming, prone to
error, low throughput
Conductivity
(Impedance)
Measures changes in
electrical resistance as cells
pass through an aperture
Fast, accurate for
counting and sizing
cells
Limited detail on cell
morphology or internal
structure
Dark Field
Side illumination with light
scattering
High contrast, detailed
morphological insights
Limited use in automated
counters, less quantitative
data
MAINTENANCE PROCEDURES
Maintaining a blood cell counter (hematology analyzer) is crucial to ensuring its accuracy,
efficiency, and longevity. Regular maintenance procedures prevent breakdowns, reduce
downtime, and improve the reliability of results. Maintenance can be categorized into daily,
weekly, monthly, and periodic procedures. Below is a detailed list of common maintenance
procedures for blood cell counters:

25. 1. Daily Maintenance
Daily maintenance tasks are performed to keep the machine running smoothly and to prevent
contamination or malfunction.
Procedures:
Cleaning the Sample Probe:
oThe sample probe should be cleaned to avoid clogs and cross-contamination
between samples. This can involve running a cleaning solution or manually
wiping the probe with a lint-free cloth.
Flushing the Fluid Lines:
oThe hydraulic system and fluid lines should be flushed daily with a cleaning
solution to prevent clogging and ensure proper sample flow.
Checking Reagent Levels:
oEnsure that the reagents (diluents, lysing agents, cleaning fluids) are at
appropriate levels. Replace them if necessary to avoid interruptions during testing.
Waste Container Check:
oEnsure that the waste container is not full and is properly connected to the system.
Empty it as needed to prevent overflow.
Background Count Check:
oPerform a background check to ensure the machine is functioning properly
without any interference. This ensures the counter is not counting air bubbles or
contaminants as cells.
2. Weekly Maintenance
Weekly maintenance procedures involve more thorough cleaning and performance checks to
ensure the analyzer’s accuracy and optimal performance.
Procedures:
Clean the Flow Cell/Optical Chamber:

26. oIf the analyzer uses optical methods (e.g., light scattering or flow cytometry),
clean the flow cell to prevent debris from interfering with the light path and
causing inaccurate readings.
Check Tubing and Connections:
oInspect all tubing and fluidic connections for leaks, kinks, or wear. Replace any
damaged or worn-out tubing to prevent issues with fluid flow.
Perform Quality Control (QC) Tests:
oRun quality control samples to verify that the machine is producing accurate and
reliable results. Compare the results with known standards to ensure the machine's
calibration is correct.
Inspect the Hemoglobin Measuring Unit:
oFor analyzers that measure hemoglobin optically, check the hemoglobin chamber
for cleanliness and perform any necessary cleaning to ensure accurate
measurements.
3. Monthly Maintenance
Monthly maintenance tasks typically involve more detailed inspections and cleaning of internal
components.
Procedures:
Check and Replace Filters:
oAir or fluid filters should be checked and replaced to prevent contaminants from
entering the system.
Calibrate the Analyzer:
oCalibrate the machine using calibration materials provided by the manufacturer.
This ensures the accuracy of all measurements, including cell counts and
hemoglobin levels.
Check Electrode Integrity (for impedance-based analyzers):
oInspect the electrodes used for measuring impedance for wear and tear. Clean or
replace them if needed to maintain accuracy.

27. Clean and Inspect the Apertures:
oClean the apertures through which blood cells pass to prevent clogging, which
could affect the counting process.
4. Periodic Maintenance (Every 3-6 Months)
Periodic maintenance is more comprehensive and may require specialized tools or the assistance
of trained service technicians.
Procedures:
Software Updates:
oEnsure the analyzer’s software is up-to-date by checking for any updates from the
manufacturer. Updated software can improve performance and accuracy, as well
as introduce new features or fix bugs.
Lubricate Moving Parts:
oApply lubricant to any mechanical parts that require it, such as syringe or piston
mechanisms, to prevent wear and maintain smooth operation.
Thorough Cleaning of Hydraulic System:
oPerform a thorough cleaning of the entire hydraulic system, including fluid lines,
to remove any accumulated debris or biofilm.
Replace Wearable Components:
oCertain components, such as seals, O-rings, or tubing, may need to be replaced
every few months to prevent leaks or failures.
Detailed Optical System Cleaning:
oIf the analyzer uses lasers or optical detectors, the entire optical system should be
inspected and cleaned to remove any dust or residue that could interfere with light
scattering or detection.
Verify Calibration with External Standards:
oUse external calibration standards provided by third-party laboratories to ensure
the analyzer’s accuracy across different parameters.
5. Annual Maintenance

28. Annual maintenance tasks are more extensive and may require service by trained professionals
from the manufacturer or authorized service providers.
Procedures:
Complete System Overhaul:
oA comprehensive inspection and overhaul of the entire system, including all
mechanical, optical, and hydraulic components, should be done to maintain long-
term accuracy and functionality.
Replacement of Major Components:
oMajor components such as pumps, sensors, or even the laser (in laser-based
analyzers) may need to be replaced after prolonged use.
Performance Qualification:
oAfter completing annual maintenance, the machine should undergo a performance
qualification process to ensure that it is meeting all manufacturer specifications.
6. Troubleshooting and Emergency Maintenance
Occasionally, issues may arise that require immediate attention, such as error messages, incorrect
results, or machine malfunctions. In these cases, emergency maintenance procedures need to be
followed.
Procedures:
Error Code Diagnostics:
oFollow the machine’s manual to identify error codes and troubleshoot the issue.
Clear Clogs or Blockages:
oIf the machine indicates a blockage in the sample probe or fluid lines, clean and
clear the blockage to restore normal function.
Re-run Quality Control Tests:
oIf abnormal results are detected, re-run quality control samples to verify the
machine’s performance.

29. SAFETY PROCEDURES
Safety procedures for using blood cell counters (hematology analyzers) are essential to protect
laboratory personnel, ensure accurate results, and prevent contamination or accidents. Proper
handling, use, and maintenance of the equipment help minimize the risk of exposure to
bloodborne pathogens and other hazardous substances. Here’s a comprehensive overview of
safety procedures when working with blood cell counters:
1. Personal Protective Equipment (PPE)
Using appropriate PPE is critical when handling blood samples and operating a blood cell
counter.
Procedures:
Gloves: Always wear disposable gloves when handling blood samples to prevent
exposure to infectious agents.
Lab Coats or Gowns: Wear a laboratory coat or gown to protect your clothing and skin
from potential spills or splashes.
Face Protection: Use safety goggles or a face shield if there is a risk of splashing during
sample processing.
Mask: Wear a mask if aerosols or splashes may be generated while handling blood
samples.
Closed-Toe Shoes: Wear appropriate footwear to prevent injury from spills or dropped
equipment.
2. Proper Handling of Blood Samples
Blood samples may contain infectious agents, so it’s essential to follow proper protocols when
collecting, transporting, and handling samples.

30. Procedures:
Label Samples Properly: Ensure that all blood samples are clearly labeled to avoid mix-
ups or misidentification.
Avoid Aerosol Formation: When handling open tubes or preparing samples for the
counter, minimize actions that could cause aerosols, such as forcefully pipetting or
shaking.
Use Biosafety Cabinets if Necessary: If working with high-risk samples, consider using
a biosafety cabinet to protect both the user and the environment from exposure.
Transport Samples Safely: Use sealed containers or bags to transport blood samples to
the analyzer, preventing spills or leaks.
3. Instrument Safety
Proper use and maintenance of the blood cell counter itself are essential to ensure operator safety
and avoid accidents.
Procedures:
Training: Only trained personnel should operate the blood cell counter. Ensure that all
users are familiar with the machine's operation manual, including emergency shutdown
procedures.
Electrical Safety: Ensure that the machine is plugged into a properly grounded electrical
outlet. Do not operate the equipment with damaged power cords or in wet conditions.
Keep Fluids Away from Electronics: Avoid spilling reagents or cleaning fluids on
electrical components. If a spill occurs, unplug the device and clean it according to the
manufacturer’s instructions.
Machine Calibration: Regularly calibrate and maintain the analyzer to prevent
malfunctions that could pose a safety risk.
Safe Loading of Samples: Always ensure that the sample probe is clear before loading
new samples. Avoid touching the sample probe directly to prevent injury or
contamination.

31. 4. Decontamination and Cleaning
Routine cleaning and decontamination of the blood cell counter are necessary to prevent
contamination and reduce exposure to hazardous substances.
Procedures:
Wipe Down Surfaces: Regularly clean and disinfect all surfaces of the blood cell counter
using an appropriate disinfectant (e.g., 10% bleach solution, alcohol) after each use.
Decontaminate Fluid Lines: Flush the fluidic system with cleaning reagents as per the
manufacturer’s instructions to avoid contamination or the buildup of biofilm inside the
system.
Handling Waste: Properly dispose of biohazardous waste, such as used reagents,
cleaning solutions, and waste from the analyzer. Use designated biohazard containers.
Spill Cleanup: If a spill occurs, follow proper biohazard spill protocols. Wear gloves and
use absorbent materials to clean the spill, then disinfect the area with a bleach solution or
other appropriate disinfectant.
5. Sharps Safety
If the blood cell counter uses needles or other sharp instruments, it’s important to follow sharps
safety protocols.
Procedures:
Dispose of Sharps Properly: Place all used needles, lancets, or other sharp items in a
puncture-resistant sharps container. Never attempt to recap needles after use.
Use Safety Devices: If available, use safety-engineered devices like needle guards to
reduce the risk of accidental puncture injuries.
Never Handle Sharps Directly: Avoid handling broken glass, slides, or other sharp
items directly. Use forceps or tongs to pick up broken materials.
6. Ergonomics and Injury Prevention

32. Ergonomic safety helps prevent injuries, especially for laboratory personnel who work with
blood cell counters for extended periods.
Procedures:
Proper Posture: When operating the analyzer, ensure that the workstation is set up to
avoid repetitive strain injuries. Maintain good posture, and adjust the height of chairs and
counters as needed.
Avoid Repetitive Movements: Take breaks if working long hours to avoid fatigue or
repetitive stress injuries, particularly during high-throughput sample processing.
Heavy Lifting: If the machine or related equipment is heavy, use proper lifting
techniques or ask for assistance to avoid injury.
7. Handling Reagents and Chemicals
Blood cell counters use various reagents for dilution, lysis, and cleaning. Handling these
chemicals safely is essential to avoid exposure and harm.
Procedures:
Read Safety Data Sheets (SDS): Before using any reagent, read its Safety Data Sheet to
understand the hazards and proper handling procedures.
Use in Well-Ventilated Areas: Ensure that reagents, especially those that emit fumes,
are used in well-ventilated areas or under a fume hood.
Wear Gloves and Protective Clothing: Always wear gloves when handling chemicals
to prevent skin contact. If reagents are particularly hazardous, wear additional protective
equipment as required.
Proper Storage: Store all reagents according to the manufacturer’s instructions, away
from direct sunlight or heat sources, and in designated chemical storage areas.
Dispose of Chemicals Safely: Follow institutional protocols for the disposal of chemical
reagents. Never pour reagents down the drain unless explicitly stated as safe in the SDS.
8. Emergency Procedures

33. In case of an emergency, such as equipment malfunction or exposure to hazardous substances,
follow the established safety protocols.
Procedures:
Equipment Shutdown: If the analyzer malfunctions, follow the manufacturer’s
emergency shutdown procedure to avoid injury or damage to the machine.
Spill Response: In case of reagent or sample spills, use appropriate spill kits and follow
biohazard or chemical spill procedures to clean up safely.
Exposure Response: If exposed to blood, chemicals, or other hazards, follow your
laboratory's exposure control plan. This includes immediately washing the affected area
and reporting the incident to a supervisor.
Fire Safety: Ensure that fire extinguishers are readily available and staff are trained on
how to use them in case of an emergency.
9. Waste Disposal
Safe disposal of biological and chemical waste is critical to preventing contamination and
environmental hazards.
Procedures:
Biohazard Waste: Place all contaminated materials (e.g., gloves, sample tubes, used
wipes) in biohazard bags or containers and dispose of them according to institutional
protocols.
Sharps Waste: Dispose of all sharp instruments (needles, lancets) in puncture-proof
sharps containers to prevent injury.
Chemical Waste: Collect used reagents in designated chemical waste containers and
dispose of them following institutional guidelines for hazardous waste disposal.
10. Training and Documentation
Ensuring that all laboratory personnel are adequately trained and that procedures are documented
helps maintain a culture of safety.

34. Procedures:
Regular Training: Provide regular training on equipment use, safety protocols, and
emergency procedures to all staff members who operate the blood cell counter.
Documentation: Maintain records of maintenance, cleaning, calibration, and safety
checks. Ensure that safety protocols are documented and accessible to all staff.
Incident Reporting: Encourage reporting of all safety incidents, accidents, or near
misses to ensure continuous improvement in safety practices.
CALIBRATION OF BLOOD CELL COUNTERS
Calibration of blood cell counters is essential to ensure the accuracy and precision of cell counts
and measurements. Calibration adjusts the instrument to match known standards, ensuring that
results are consistent and reliable over time. This process is critical in clinical diagnostics, where
accurate blood cell counts are essential for diagnosing and monitoring diseases.
Here is a comprehensive overview of the calibration process for blood cell counters:
1. Purpose of Calibration
Ensure Accuracy: Calibration ensures that the blood cell counter provides accurate
readings that align with known reference values.
Consistency Across Samples: It ensures that all measurements taken by the machine
over time remain consistent and reliable.
Regulatory Compliance: Calibration helps meet regulatory and quality control
standards, such as those set by health authorities and accrediting bodies (e.g., CLIA,
CAP).
Prevent Drift: Over time, sensors and other components may experience drift, which can
lead to inaccurate readings. Calibration corrects for this drift.
2. Types of Calibration

35. There are several different types of calibration used for blood cell counters, depending on the
type of machine and the parameters being measured:
a. Instrument Calibration
This involves adjusting the overall functionality of the blood cell counter to ensure it is working
within manufacturer specifications.
Conductivity/Impedance Calibration: For cell counters using the impedance method,
calibration ensures the system accurately detects cell size and count by measuring
changes in electrical resistance.
Optical Calibration: For cell counters that use optical methods (e.g., light scattering),
calibration ensures that the light sources, detectors, and optical paths are aligned and
functioning correctly.
b. Calibration for Different Cell Types
Red Blood Cells (RBCs): Calibration ensures accurate counting and measurement of
RBC size (mean corpuscular volume - MCV).
White Blood Cells (WBCs): Calibration ensures correct differentiation and counting of
WBC types (lymphocytes, neutrophils, monocytes, etc.).
Platelets: Calibration ensures accurate platelet counts and platelet volume (mean platelet
volume - MPV).
c. Hemoglobin Calibration
For machines that measure hemoglobin levels, calibration is necessary to ensure accurate
spectrophotometric measurement of hemoglobin concentration in blood.
3. Calibration Materials
Calibration requires the use of standard materials with known values. These materials are used to
adjust the machine's settings.

36. a. Commercial Calibrators
Manufacturers provide calibration standards specifically designed for use with their blood cell
counters. These are control samples with known cell counts and characteristics.
Blood Cell Standards: These contain cells (or synthetic particles) with a known
concentration, size, and distribution to ensure the machine measures correctly.
Hemoglobin Standards: For hemoglobin measurement, calibrators with a known
concentration of hemoglobin are used.
b. Reference Blood Samples
In some cases, reference blood samples with a known cell count and distribution (validated by
another method) are used for calibration purposes.
4. Calibration Procedure
Calibration involves a series of steps that must be carefully followed to ensure accuracy.
Although specific steps may vary by manufacturer, the general procedure includes:
Step 1: Warm-Up and Preparation
Machine Warm-Up: Ensure that the blood cell counter is turned on and has completed
its warm-up cycle before calibration.
Prepare Reagents and Samples: Ensure that all reagents and control materials are at the
correct temperature and properly mixed.
Background Check: Run a background check to verify that the machine is functioning
properly without any contamination or interference.
Step 2: Load Calibration Materials
Select Calibrators: Load the calibration materials (cell standards or reference samples)
into the machine.

37. Run Calibration Mode: The blood cell counter typically has a calibration mode or
function in its software. Select this mode and initiate the calibration process.
Step 3: Adjust Parameters
Check Results: The machine will measure the calibration material and compare the
results to the known standard values.
Adjust Instrument Settings: If the machine's measurements do not match the standard
values, adjust the instrument's settings (e.g., voltage, gain) according to the
manufacturer’s instructions.
Repeat Measurements: After adjustments, run the calibration sample again to ensure
that the readings match the standard values.
Step 4: Verification
Run Quality Control (QC) Samples: After calibration, run QC samples with known
values to verify the accuracy of the calibration. These samples ensure the machine
produces accurate results within the acceptable range.
Document Calibration: Record the calibration results and adjustments in a logbook or
electronic system to maintain compliance with regulatory requirements.
5. Frequency of Calibration
Calibration should be performed regularly to maintain accuracy. The specific frequency depends
on the laboratory’s protocols, the type of blood cell counter, and regulatory requirements.
Daily or Weekly Calibration: Some high-use laboratories calibrate the machine daily or
weekly to ensure precision.
Monthly Calibration: Most analyzers require at least monthly calibration as part of
regular maintenance.
After Maintenance: Always perform calibration after any major maintenance or repairs
(e.g., replacing electrodes or sensors).

38. After Reagent Changes: If reagents or calibration materials are replaced with a new lot,
recalibrate the analyzer to ensure consistency.
6. Quality Control After Calibration
Even after calibration, it is essential to run regular quality control (QC) checks to ensure
continued accuracy. This involves running known control samples with each batch of patient
samples.
Control Limits: Ensure the QC samples fall within the expected control limits. If the
results are outside these limits, recalibration may be necessary.
Daily QC: Run QC samples at the beginning of each shift or day to verify the machine’s
accuracy.
7. Common Issues and Troubleshooting in Calibration
Sometimes calibration may fail or produce inaccurate results. Common issues include:
Clogged Apertures: Debris or clots in the sample probe or apertures can cause incorrect
counts, requiring cleaning before calibration.
Reagent Problems: Using expired or contaminated reagents can lead to inaccurate
results. Always check reagent expiration dates and lot numbers.
Electronic Drift: Over time, the electronics in the machine can drift, causing
measurements to become inaccurate. Regular calibration corrects for this.
Incorrect Calibration Material: Ensure the calibration material is suited for the specific
blood cell counter model.
8. Calibration Documentation and Records
Proper documentation is critical for compliance with regulatory agencies and to maintain
laboratory accreditation. Records should include:
Date and Time: When the calibration was performed.

39. Calibration Materials: The type of materials used for calibration, including lot numbers
and expiration dates.
Results: Record pre- and post-calibration results, as well as any adjustments made.
Technician Information: The name of the person performing the calibration.