Specimen collection and handling

A brief presentation on specimen collection and handling on some of the routine tests carried out in district hospitals in Malawi.

1. SPECIMEN
COLLECTION AND
HANDLING
Symon Fidelis Nayupe
BSc Medical Laboratory Sciences [Honors]

2. OBJECTIVES
•Responsibility of specimen collection
•How to collect and handle various specimens
•Sample rejection

3. Introduction
•Nurses often assume the responsibility of sample
collection – wards
•Proper sample collection and handling ensures
quality and reliable lab results – sample
degradation or compromise
•Necessary for sample collectors to know and abide
by proper sample collection and handling
techniques

4. Specimen collection key
issues
•Consider differential diagnoses
•Decide on test(s) to be conducted
•Decide on clinical samples to be collected to
conduct these tests
•consultation between microbiologist, clinicians and
epidemiologist

5. Specimen collection tubes
1. Ethylenediaminetetra-acetic acid [EDTA]
•Purple top/ lavender top
•Used for:
 routine haematology [FBC]
Reticulocyte count
Sickle test
 Glyco HB,
Hb electrophoresis
CD 4, thin smear, blood grouping
•Not suitable for Calcium and coagulation
•Invert several times soon after collection

6. Specimen collection tubes
cont…
2. Red top [No clot activator]
•As indicated, has no clot activator – plain
•ALL BODY FLUIDS [CSF, Ascitic, Pleural, lymph
aspirates etc] must be collected in this tube.
•Invert several times soon after collection

7. Sample collection tubes cont…
3. Red top, with clot activator.
•Used for chemistry, crossmatch, serology [VDRL,
Hep B and C]
•Invert several times after collection

8. Specimen collection tube
cont..
4. Blood culture bottles
•Has bacterial growth medium and activated charcoal
•Sample for blood culture is collected directly into BC
bottle

9. Basic sample collection
techniques
A. Venipuncture
•Collection of blood from a vein for various tests that require
large volume sample
•Requires a tourniquet, needle, syringe, disinfectant, cotton
wool, specimen collection tubes.
•Procedure commonly done on a vein in the antecubital fossa of
the arm.
•Can also on a site other than the antecubital fossa where a vein
is visible or can be reached.
•Blood is drawn with a needle after the site has been
thoroughly disinfected, with the bevel of the need facing
upwards.

10. Blood samples – blood for
smears
Collection
Capillary blood from finger prick
•make smear
•fix with methanol or other fixative
Handling and transport
Transport slides within 24 hours
Do not refrigerate (can alter cell morphology)

11. Blood samples – blood for
cultures
Collection
Venous blood
•infants: 0.5 – 2 ml
•children: 2 – 5 ml
•adults: 5 – 10 ml
Requires aseptic technique
Collect within 10 minutes of fever
•if suspect bacterial endocarditis: 3 sets of blood culture

12. Basic sample collection
techniques
•Urine collection
•Wash hands
•Clean meatus, female front to back
•Start stream, then stop, collect specimen
•Aseptic technique
•Bedpan/mexican hat
•To lab 15-20min post collection
•Urine specimens
•Random specimens, mid-stream urine, timed urine,
sterile urine

13. Basic sample collection
techniques
•Stool specimens
•Analysis of fecal material can detect pathological
conditions ie: tumors, hemorrhage, infection
•Tests: OB, ova and parasites, pus
•Use a sterile container to collect stool.
•Applicator sticks, direct collection, stool sample scoop.
•Must reach the lab as soon as possible

14. Basic sample collection
techniques
•Vaginal or Urethral Discharge Specimens
•Normally thin, nonpurulent, whitish or clear, small
in amount
•STD’s, UTI
•Not Delegated
•Assess external genitalia
•If STD record sexual history
•Physician’s order- vaginal/urethral

15. CSF
•Collection
•Lumbar puncture
•Sterile tubes
•Aseptic conditions
•Trained person

16. CSF
•Handling and transportation
Bacteria
•preferably in trans-isolate medium,
pre-warmed to 25-37°C before inoculation
OR
•transport at ambient temperature (relevant pathogens
do not survive at low temperatures)
Viruses
•transport at 4-8
o
C (if up to 48hrs or -70
o
C for longer
duration)

17. Common sample collection
techniques – sputum
Collection
Instruct patient to take a deep breath and cough up
sputum directly into a wide-mouth sterile container
•avoid saliva or postnasal discharge
•1 ml minimum volume

18. Rejection of samples
•All samples collected in wrong tubes are rejected
•All samples untimely brought to the lab are
rejected
•Unlabeled samples are rejected
•Insufficient samples are rejected
•Compromised samples [haemolysed etc] are
rejected
•If a sample is rejected, the one rejecting it must
indicate the reason for the rejection of the sample.

19. References
•Lieseke CL, E Ziebig; Essentials of Medical
Laboratory Practice, 1
st
Edi., FA Davis Company,
Philadelphia, USA [2012]