**5. Phage Amplification Technique (PAT)**

This is a bacteriophage based test to detect MTB in sputum. Non-pathogenic mycobacteria (sensor cells) were used for control bacteria in the test. The phage replicate, infect and lyses the sensor cells leaving zones of clearing (holes) in the agar. The areas of clearing indicates that the patient sputum contain viable MTB. It is fast with a turnaround time of 2 days. It is cheap, requires few equipments, sensitive (detection as low as 100 tubercles per ml of spu‐ tum). It can be adapted for sensitivity testing. Limitations are applicability to sputum speci‐ men only and technically demanding [22].
