pipetting - pipettes classification.pptx

pipettes uses
classification
guidelines to use pipette

1. PIPETTING AND its CALIBRATION

2. CONTENTS INTRODUCTION CLASSIFICATION PIPETTING TECHNIQUE PIPET TE TERMS MICROPIPETTE CRITERIA FOR PIPETTE SELECTION PIPETTE CALIBRATION

3. INTRODUCTION Cl inical Chemistry Procedures Require Accurate Volumetric Measurements for Accurate Results Pipettes Used For The Transfe r Of A Volume Of Liquid From One Container To Another Container . Pipettes used in Clinical laboratory Molecular diagnostic lab Analytical laboratories Manual Tra nsfer & Measuring Micropipette Electronic & mechanical

4. CLASSIFICATION OF PIPETTES B ased on DESIGNS A. To Contain [TC] B. To Deliver [TD] 2. Based on DRAINAGE CHARECTERISTICS a. Blowout b. Self-draining 3 . Based on TYPE A.MEASURING / GRADUATED a. serologic b. Mohr c. Bacteriologic d. ball/ kolmer / kahn e. Micropipette B. TRANSFER a. Volumetric b. Ostwald- Folin c. Pasteur pipettes d. Automatic macro & micro pipettes

5. MEASURING PIPETTE Graduated or measuring pipette Graduated uniformly Drawn out to a tip use: a.Measuring of reagent 1.Mohr pipette 2.Serological pipettte MOHR PIPETTE SEROLOGICAL PIPETTE Calibrated B/W 2 marks on the stem Graduated marks down to tip Blown out Controlled delivery Smaller orifice Larger orifice Slower than serological Faster drain Long tips, Tapered delivery tip, tip should not touch the vessel while draining Tapered delivery tip Uniform diameter Uniform diameter Self draining

6. PIPETTING TECHNIQUE 1. Always Use Pipetting Bulb 2. Pipettes Must Be Held In Vertical Position 3. Read At Eye Level 4. Coloured Solution At Higher Meniscus , Colourless Solution At Lower Meniscus. 5. Tips Should Be Touched To The Inclined Surface , 2 Seconds After Stopping Of Flow 6. In Graduaded Pipette, The Flow Have To Be Slow 7. In Blow Out Pipette ,It Is Allowed To Drain And Then Remaining Is Blownout 8. Unrestricted Flow 9. Not Touching The Vessel Wall 10. Avoid MOUTH PIPETTING

7. MENISCUS READING D/t surface tension of liquid

8. TERMS ADJUSTMENTS altering the pipette ASPIRATE to draw up the sample DISPENSE/ DISTRIBUTION to deliver the solution CALIBRATION CHECK to check the difference b/w dispensed and selected volume ACCURACY the degree of closeness of volume indicated and dispensed PRECISION reproducibility the degree of closeness to which measurements show the same or similar results PURGE means blow out

9. PARTS OF MICROPIPETTE

10. MICROPIPETTE Measurement of microliter volumes notable error due to coating of inner wall Requires rinsing Volumes as microliter / lamda {1 micro liter=0.001 ml } Availabilty from 1 to 10 00 micro liter & may upto 0.2 micro L It may fixed or adjustable

11. ADVANTAGES OF MICROPIPETTE Adjustable ergonomic designs multiple wells piston driven Stability Safety Easy Disposable tips No washing / drying Time saving Avoid cross contamination Improve precision

12. STEPS FOR OPERATING MICROPIPETTE Set the volume Attach disposable, correct tip Depress the plunger to the first stop Immerse tip in sample Draw Pause Dispense the sample by depressing the plunger to 1stop pause press the plunger to 2 stop to expel the residual Withdraw the tip Release the plunger Discard the tip

13. TYPES OF MICROPIPTTE 1 . Air Displacement 2. Positive displacement 3. Dilutor / dispensor 4. M ultichannel / single channel 5. Automatic / Electronic Fixed Adjustable

14. 4. MULTI CHANNEL / SINGLE CHANNEL MICROPIPETTE

15. 5. AUTOMATIC OR ELECTRONIC PIPETTE the most routinely used pipette in clinical chemistry laboratory. Advantages : safety, stability, ease of use, increased precision, the ability to save time, Less cleaning required MICROPIPETTE pipetting capability < 1 mL , MACROPIPETTE pipetting capability >1 mL

16. GENERAL GUIDELINES TO USE PIPETTES Wipe with 70% ethanol or 60% iso propanol Set the volume P ipette and tip @ same temp Recommended tip Single use tip When liquid is in the tip avoid inverting 8.Avoid finger contamination 9.Use pipette stands

17. RISK FACTORS Repetitive motion & excess force of thumb & wrist Postures For c ed gripping Holding the hand in elevated position & distant from the body PREVENTING CROSS - CONTAMINATION Pipette to sample Sample to pipette Sample to sample

18. TIP SELECTION Use recommended tips only Pure poly propylene No dust / particles Uniform size & shape Center tip orifice Free from metal like CADMIUM --? Sealing Free from protrusions Resistant to chemicals 10. Thermally stable 11. Reproducibility