The specimen collection is based on which organism might be deemed pathogenic for the particular body site. In addition, the laboratory method (culture or PCR) will dictate the proper body site and type of specimen to collect from that body site.
General Collection Notes
The majority of specimens submitted to the laboratory will consist of swab specimens. However, urine or blood may also be submitted - depending on the test method performed by the specific laboratory. Blood cultures have a completely different collection protocol, as noted below:
- Acceptable specimens include body fluids, tissues, wound swabs, nasopharyngeal/throat swabs, and urethral/cervical/vaginal swab specimens. Rectal swabs may also be acceptable depending on the organism and specific test method.
- Swab specimens should not contain any lubricants, antiseptics, or analgesics. Dacron or polyester swabs on aluminum or plastic shafts should be used.13 If possible, use a flocked swab. Do not use calcium alginate swabs or swabs with wooden shafts. (These may contain substances that inactivate substances or interfere with molecular assays.)
- Urine is an acceptable specimen for many test methods; however, avoid contamination with lubricants and antiseptics during collection. First-voided specimens are preferable.
- Blood (for culture) is an acceptable specimen; however, mycoplasmas are inhibited by sodium polyanethol sulfonate (SPS) anticoagulant found in commercial blood culture bottle media. In addition, automated instrumentation is inadequate. Blood is thus collected into a specific broth culture medium (refer to test method/specific lab instructions) - usually, 10B or SP4 broth medium.
Unacceptable specimens
The following are usually considered unacceptable specimens and will be rejected by the laboratory performing the testing:
- Wrong source, or no source listed.
- Incorrect collection media/kit used. (See next page for additional detail.) Always seek guidance from the reference laboratory or test package insert.
- Use of wooden shaft, cotton-tipped swabs.
- Nonpatient specimens.
- Dry swabs.
- Tissues submitted in embedding compound (as used in frozen sectioning).
13. Tille PM. Bailey & Scott's Diagnostic Microbiology. 15th ed. Elsevier. 2022.
