Sample Collection and Transport Techniques

Collection and Transport of Samples

• Morphological Substances (Lesioned Organs): Hand-sized lesioned organs are transported in saline with 50% glycerin. Glycerin has a bactericidal effect if delivered over a long period.

• Blood Samples: Use anticoagulants like EDTA or heparin for serological and biochemical analysis. Collect blood via a venous route. Shave or remove hair and clean the area with 70% alcohol before drawing blood. Mix anticoagulated samples immediately after collection, inverting the tube.

• Serum Samples (Gel Tubes): Use gel tubes for serum samples. Allow blood to clot at room temperature for 1-2 hours, then seal and refrigerate for several hours or overnight. Centrifuge at 1000 rpm for 10-15 minutes.

• Serum: Serum is the liquid portion separated from a clot formed by fibrinogen's transformation into fibrin. The serum does not contain fibrinogen as it is the liquid portion that is separated from the clot.

• Plasma: Plasma is the cell-free liquid component of blood treated with anticoagulants. Collect blood with anticoagulants, centrifuge the blood sample at 3000-3500 rpm for 30 minutes, and use the upper liquid as plasma.

• Stool and Bowel Content: Transport faecal samples in appropriate medium at 4°C. If same day delivery is impossible, add 5 drops of chloroform to 50ml of small bowel content. For mastitis diagnosis, take 5-8 ml of the first milk from the udder. Deliver samples within 24-48 hours if the laboratory requires cold chain adherence. Add 5cc of 10% Boric Acid if delivery is delayed for 2 days.

• Eye and Nasal Discharge: Collect samples (saliva, tears) by swabbing the conjunctiva. Place swabs in transport medium; swab should be in contact with secretions for a minute. Deliver to lab immediately at 4°C.

• Abscesses: Collect scrapings from the abscess wall. Pus from the middle of abscesses is usually sterile. Best results are achieved by collecting samples from newly-formed abscesses.

• Abortion Samples: Collect fetal abomasal content (ruminants), lesions, and potentially infected placental material (2 or more cotyledons). Collect 20ml of uterine discharge and parent urine for further investigation. Serum samples should be taken for serological tests.

• Urine Samples: Urine should be delivered for analysis, microscopy, culture, and clinical bacteriuria detection. Collect samples in sterile containers. Do not allow bacteria to come in contact with the samples. Prefer cystocentesis, catheter, or mid-stream urine to collect samples. Samples should be inoculated within 4 hours.

• Genital Discharge and Semen: Collect samples using vaginal or preputial washing (use swabs to collect). For semen use an artificial vagina. Specific transport medium needs are often required. Deliver biopsy or scraping samples from infected skin lesions in sterile condition to the lab as soon as possible. If for fungal infections, scrape and collect nails or other lesions. Wipe with 70% alcohol, then use forceps, curette or scalpel to collect and place in sterile containers. Seal.

• Acceptance Criteria: Samples should be very fresh and in sufficient quantities for testing. Ideally, samples should be collected from patients when showing fever (pyretic period) for maximal detection of potential pathogens.

• Additional Requirements for Samples (Organs, Tissues): If submitting organs or tissues, materials should be suitable for bacteriological examination. Collect from fresh cadavers within 2 hours of death to use for examination. Store and transport under cold chain. Samples should be taken without the use of antibiotics, or before antibiotic administration. Wait for the antibiotic period to end before collecting.

• Morbid Substance Handling: Collect these under aseptic conditions, place them in sterile containers, and rapidly transport them to the lab under refrigeration (cold chain). Sterilize laboratory equipment if needed. The label information should be complete and accurate for the examination.