TAKING MICROBIAL CULTURES AT AUTOPSY     Identification of microorganisms from tissues at autopsy may often be useful. This is especially true when lesions suspected of having a microbiological origin (abscess, bacterial endocarditis, etc.) are met without having been tested during life.     Prosectors are expected to use judgment before sending specimens for culture, especially if multiple cultures are being considered. If one is in doubt it may be best to take the specimen for culture and then proceed with dissection, etc. before deciding to send it. However, upon receipt specimens should be delivered as soon as reasonable possible to the micro-biology lab in Clinical pathology (Rm CL 5040), and they should not bee held for more than an hour, or two at the most.     To minimize contamination take the specimen as early as possible during the dissection. For instance, a blood culture should be taken early so as to minimize the artefactual spreading of organisms ( and before any of the major vessels have been cut because the resulting collapse makes it difficult to aspirate enough blood into the syringe). For localized lesions, cutting into a space or tissue with a nonsterile knife almost necessarily causes contamination; this may not be preventable if the lesion has not been suspected. However, it is just poor technique to dissect or handle the specimen more than necessary.     Time delay in taking the specimen is also undesirable. BACTERIA Blood Culture: One good method is to sear the external surface of the right atrium with a flamed spatula (after opening the pericardial sac in situ), then with a sterile needle and syringe aspirate 10 mls (postmortem clots may cause slight difficulty here). Disinfect the top of the yellow-stoppered SPS tube with 70% alcohol and inject the blood through it. Culture of Tissue: Use as sterile a technique as possible; flame forceps and scalpel beforehand. Place a small pier (1/4 - 2 grams, depending on size of lesion) of the tissue in a sterile tube or cup with cover. Transport medium is not recommended unless there will be a delay of several hours before plating. Culture of Fluid (pus or fluid) from Serous Cavity: With or without a needle aspirate up to 10 mls into a sterile syringe, which may be taken to the lab. Swabs in Ames Transport Medium: These maybe used to sample a minute amount of fluid or to take a culture from a surface, such as pleural. They replace the swabs in the tube. Take at least one swab for each type of culture requested (routine, acid-fast, fungus). However, if enough material can be collected in a container one may get all of these types of cultures from a single specimen. VIRUSES     Place a few grams of tissue or exudate in a sterile container and get this to the lab ASAP. If there is any delay the specimen should be refrigerated. FUNGI     Identification of the genus (for example, candida, aspergillus, cryptococcus, etc.) of fungi in tissue can be recognized in H & E sections (but are more easily and reliable identified with PAS or GMS-stained sections). Therefore, cultures for fungi are seldom needed unless one wishes to identify the particular species (such as the species flavus or fumigatus of the genus aspergillus).