Mycobacterium tuberculosis complex PCR, tissue

Test Mnemonic


CPT Codes

  • 87556 - QTY (1)
  • 87496 - QTY (1)


  • M. tuberculosis PCR, tissue
  • TB PCR, tissue

Performing Laboratory

University of Washington Molecular Microbiology

Days Performed

Mon - Fri

Turnaround Time

2 - 3 weeks


Name Description
Polymerase Chain Reaction (PCR) 

Reference Range

Special Info

Specimen source must be included.

Clinical Info

Although an acid fast smear can provide an important clue to the nature of the causative agent, a positive result does not necessarily indicate the presence of M. tuberculosis complex. The presence of acid fast bacilli in clinical specimens can be simply due to the growth of common water contaminants such as M. chelonae and M. fortuitum. On the other hand, a negative smear does not rule out the presence of M. tuberculosis complex at low pathogen load. The use of PCR to detect this DNA extracted directly from clinical specimens facilitates the identification of these pathogens.