Specimen Collection and Transport in the Physician Office Laboratory

Learning Objective: Examine the procedures for specimen collection and transport in the physician office laboratory.
      Specimen collection and handling are important considerations in patient care because the results are only as good as the quality of the sample. Ideally, specimens should be collected during the acute phase of an illness and before antibiotics are prescribed. Specimens for microbiology testing can include urine, stool, sputum, and blood. Sterile swabs can be used to collect samples from wounds and the upper respiratory tract.

Guidelines for Specimen Collection
Learning Objective: Explain the guidelines for specimen collection.
Specimens must be collected carefully so that contaminating microorganisms are not introduced into the specimen. This means not only using sterile collection and transport devices but also taking steps to prevent contamination. To prevent from contaminating the specimen, the person should do the following:
            • Wash hands before collecting the sample.
            • Cleanse the area involved with an antiseptic, if appropriate. For example, when obtaining a clean-catch midstream urine specimen, antiseptic wipes are used.
            • Open sterile containers only when necessary and avoid touching the inside surfaces.
            • Never touch a sterile swab or collection device on a nonsterile surface.
      If patients are expected to collect a sample, it is crucial that they receive clear instructions on how to perform the procedure correctly and without contaminating the sample. The referral laboratory is responsible for providing a manual of written instructions to the POL. The POL is responsible for providing clear oral and written instructions to the patient. If the patient will be collecting the sample in private or at home, written instructions that are simple and straightforward should be supplied.
      To protect from pathogen exposure, the medical assistant should wear the appropriate personal protective equipment (PPE) when collecting, handling, and processing specimens. The medical assistant should wear gloves, a fluid-impermeable lab coat, a surgical mask (for droplet or airborne pathogens), and protective eyewear or a face shield. Proper handwashing techniques are also important before and after the procedure.
      The following sections discuss transporting specimens and how to collect different types of specimens.

Guidelines for Handling and Transporting Specimens
Learning Objective: Explain the guidelines for handling and transporting specimens.
      The transport of specimens to referral laboratories is also crucial. Different types of transport devices are available. Close attention must be given to their proper use. Microorganisms are living organisms, so they must be given conditions that ensure their survival. Care must also be taken so that any normal flora in the sample will not multiply and overgrow possible pathogens. The type and number of microorganisms in the sample should reflect the type and number of microorganisms at the site of collection and at the time of collection.
      Specialized transport media are often included with specimen collection swabs or devices (FIGURE 35.5). Collection devices typically consist of a plastic tube that encases a sterile Dacron swab and a sealed vial of transport medium. After the specimen has been collected on the swab, it is placed in the plastic tube with the transport medium. It is essential to follow the manufacturer’s directions to prevent the swab and specimen from drying out. Transport system swabs also have a label that must be filled out completely, indicating the patient’s full name, the date and time of collection, the collector’s initials, and the source of the specimen (e.g., deep wound sample from left leg abscess).
      If possible, a specimen should be placed on culture media immediately after collection. If this is not possible, then the transport device must be sent to a referral laboratory or held in the POL until it can be cultured. For specimens that will be transported by a courier, make sure the specimen is safely packaged in a leak-proof container marked with warning labels (FIGURE 35.6). The proper time and temperature of storage are vital. Most pathogenic organisms prefer body temperatures, of approximately 37°C (98.6°F). They will remain viable for up to 72 hours if held at room temperature or refrigerator temperature (4°C [39.2°F]). Some organisms die if exposed to cold temperatures. Always check the referral laboratory’s procedure manual for directions regarding sample time and temperature of storage.
      See FIGURE 35.7 for some commonly used microbiology collection devices. Devices used for both aerobic and anaerobic blood collection are shown in FIGURE 35.7A, and BACTEC blood culture bottles are pictured in FIGURE 35.7B. Two other commonly used transportation devices are the JEMBEC plate for transporting Neisseria gonorrhoeae (see FIGURE 35.7C) and a viral-chlamydial transport medium (see FIGURE 35.7D).
      See TABLE 35.3 for a description of the specimens, containers, patient preparation processes, and storage of specimens commonly collected or handled by medical assistants.