Mycobacterial Culture, Blood
Method Description Describes how the test is performed and provides a method-specific reference
Blood is drawn in a heparin tube and must be transported to the laboratory (ambient) within 48 hours. Five milliliters of blood is then transferred to a conical 50-mL centrifuge tube and sterile distilled water is added to a final volume of 40 mL to lyse the cells. The tube is centrifuged at 3,000 x g for 20 minutes and the supernatant is decanted. Two milliliters of sterile phosphate buffer is added to resuspend the sediment, 1 mL of the suspension is added to a VersaTREK Myco bottle, and 0.5 mL is plated onto 7H10 agar. The agar plate is incubated at 37 degrees C with 5% to 7% carbon dioxide (CO2) for 42 days. The VersaTREK Myco bottle is incubated on the automated VersaTREK 528 instrument for 42 days. The instrument continuously monitors headspace pressure changes within the bottle, which correspond to gas production or consumption due to microbial growth. After a bottle signals as positive on the instrument, it is removed and a smear is performed to look for acid-fast organisms. Acid-fast organisms are identified using conventional methods including nucleic acid hybridization probes or 16S rDNA gene sequencing.(Mirrett S, Hanson KE, Reller LB: Controlled clinical comparison of VersaTREK and BacT/ALERT blood culture systems. J Clin Microbiol 2007;45:299-302; Hall L, Doerr KA, Wohlfiel SL, Roberts GD: Evaluation of the MicroSeq system for identification of mycobacteria by 16S ribosomal DNA sequencing and its integration into a routine clinical mycobacteriology laboratory. J Clin Microbiol 2003;41:1447-1453)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Sunday; Continuously
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test