Specimen Collection, Transport and Processing Flashcards
General Specimen Collection Guidelines
- Obtain during acute phase of infection (within 2–3 days
for viruses). - Collect before antibiotics are administered.
- Sample appropriate site.
- Aspirates or tissues are preferred to swabs.
- Use swabs with Dacron or polyester tips & plastic
shafts. Wood, cotton, & calcium alginate may be
toxic. - For anaerobes, aspirates preferred to swabs.
- Avoid contamination with environmental or normal
flora.
General Specimen Collection Guidelines continued
- Obtain sufficient quantity.
- Use sterile, leak-proof container.
- Properly label container, not lid.
- Transport in secondary container (plastic bag) marked
with biohazard symbol. - Protect requisition from contamination.
- Syringes with needles attached should never be
transported. - Deliver to lab within 30 min of collection.
- For prolonged transit, use special preservatives or
holding media.
Specimen Preservation and Storage
Criteria for Rejection of Specimens
in Microbiology
- Unlabeled or improperly labeled specimen
- Improper collection site
- Prolonged transit (over 2 hr without preservation)
- Improper temperature during transport or storage
- Leaking specimens
- Specimens in nonsterile containers
- Improper transport medium
- Culturette ampule not broken, swab dried out
- Improper swab, e.g., wood or calcium alginate for
viruses or Chlamydia - Syringes with needles attached
- Culture for anaerobes requested on inappropriate
sources - Specimen received in formalin (other than stool for ova
& parasites) - Saliva instead of sputum
- Foley catheter tip
- Insufficient quantity
Describe skin preparation for venipuncture
Disinfect skin with 70%-95% ethanol or isopropyl alcohol and then 2% tincture of iodine or 2% cholhexidine
Describe the recommended blood volume and ratio to culture medium for pediatric and adult blood collections.
- Ideally inoculate each of 2 blood culture bottles (1 set) with 10mL of blood from adults (20mL per set)
- Children 5-10 mL per set
- Newborns 2-4 mL per set
It is Best practice to collect how many sets of blood bottles from separate peripheral sites in 24 hours?
2
What is the purpose of Resin containing blood bottles?
To chelate antibodies and mediators of the immune system
What is the anticoagulant used in blood bottles?
Sodium polyanethole sulfonate (SPS)
A minimum of how many patient identifiers are required?
2
As a general rule of thumb, if transport and storage is >24 hours nonsterile specimens should be what?
Refrigerated
(Do not refrigerate sterile specimens!)
Describe how CSF is collected and processed?
- Generally, 4 tubes of spinal fluid are collected. The 2nd or 3rd tube should be used for culture.
- If the lab only receives enough CSF to inoculate once piece of media, an enriched medium should be used aka CHOC agar
Nasopharyngeal specimens are optimal for the recovery of what organisms?
Respiratory viruses, Corynebacterium diphtheria, Chlamydia pneumonia, and Bordetella Pertussis
Bordetella pertussis is the causative agent of Whooping Cough. If suspected, what media can be used for its recovery?
Regan Lowe or Bordet-Gengou agar
When a swab is used for bacteriologic culture, it should be placed in transport media. Name two examples of bacteriologic transport media.
Amies and Stuart
Dacron, Polyester, or Rayon tipped swabs with a plastic or aluminum shaft are recommended
