Culture Referred for Identification, Mycobacterium
Method Description Describes how the test is performed and provides a method-specific reference
The Gen-Probe AccuProbe system uses an acridinium-labeled, single-stranded DNA probe that is complementary to the ribosomal RNA of the target organism. After the ribosomal RNA is released from the organism, the labeled DNA probe combines with the target organism's ribosomal RNA to form a stable DNA:RNA hybrid. Chemiluminescence is used as an indicator to detect specific hybrids.(Musial CE, Tice LS, Stockman L, Roberts GE: Identification of Mycobacterium from culture by using Gen-Probe rapid diagnosis system for Mycobacterium avium complex and Mycobacterium tuberculosis complex. J Clin Microbiol 1988;26:2120-2123)
The DNA sequence analysis utilizes 16S rRNA as the target for identification of mycobacteria. The molecule is approximately 1,500 nucleotides in length and contains several highly variable regions flanked by area of high conservation. 16S rDNA sequence data is available for a wide variety of prokaryotic organisms. The assay procedure uses the MicroSeq kit from Applied Biosystems.
Sequence data generated from the 16S rRNA sequencing procedure is approximately 500-base pairs long and is compared to several different databases of known mycobacterial and aerobic actinomycete sequences to obtain an organism identification. These include MicroSeq, GenBank, and Mayo Clinic Mycobacteria database. A 99% or greater agreement with a database strain is needed for an acceptable identification.(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
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
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