The Molecular Microbiology section deals with Polymerase Chain Reaction (PCR) based diagnostic assays for Infectious Diseases like Tuberculosis (TB), Human Immunodeficiency Virus (HIV), Hepatitis B Virus (HBV), Hepatitis C virus (HCV), etc. The laboratory is state-of-the-art and fully equipped with advanced instrumentation like real-time PCR machines and end-point gradient PCR systems.
Working protocols have been devised as per the College of American Pathologists (CAP) guidelines; as recommended, the laboratory follows a unidirectional work flow with designated physically separate areas for pre-amplification, nucleic acid extraction, amplification, and post-amplification activities.
Each designated area has dedicated instruments like pipettes with aerosol barrier filter tips, centrifuges, bio-safety cabinets and deep freezers in order to minimise aerosol and PCR amplicon contamination. Testing is performed according to biosafety level II standards; the initial steps carried out for TB related tests are performed in the Mycobacteriology section up until the heat killing. Validation studies are performed for each assay prior to testing patient samples. All assays include appropriate positive and negative controls in keeping with Quality Control (QC) practices.
The laboratory participates in proficiency testing programs conducted by CAP. New reagent lots are checked against old reagent lots using clinical samples or external QC material. All instruments in the laboratory are maintained as per CAP norms with regular QC and preventive maintenance carried out at recommended intervals. Results of assay controls are reviewed for acceptability prior to reporting patient results. If QC results exceed defined acceptability limits, appropriate corrective action is initiated.
Positive TB PCR reports, reports of detection of drug resistance of Mycobacterium, are critical and informed to the consultant doctor. Reports critical for infection prevention are informed to the Infection Control Nurse. The laboratory primarily carries out molecular tests for the detection of Mycobacterium tuberculosis (MTB) in various pulmonary and extra-pulmonary specimens like sputum, bronchoalveolar lavage, pleural fluid, ascitic fluid, pus, etc., the results of which are ready in 48 hours. Further advanced testing for drug resistance in MTB is done by the Hain’s test, which can be performed from the Mycobacterium culture or an AFB smear positive clinical specimen, the results of which are ready in 48 hours.
As the laboratory is one of the few specialised in molecular biology in a large tertiary care hospital in Mumbai’s western suburbs, the patient base is growing steadily and new assays will be included in the testing menu in the future. The Molecular Microbiology section is committed to strongly support clinical decision making at the hospital with regards to molecular diagnosis of Infectious Diseases.
Molecular Microbiology Laboratory is a separate, fully automated laboratory for detection of viral and bacterial nucleic acid by real time PCR (Polymerase Chain reaction) used for diagnosis and prognosis for infectious diseases like Influenza (including H1N1), Tuberculosis, HIV, Hepatitis viruses, Cytomegalovirus (CMV) and Herpes Simplex Virus (HSV). The entire laboratory is under negative pressure (to protect Health care workers & environment) and is fully equipped to be used as regional centre if there is an unknown new infectious outbreak. The lab is approved by Municipal Corporation of Greater Mumbai (MCGM) for testing of H1N1 and is in close liaison with the Epidemiology Cell.
Automated ELISA machine helps providing accurate results within short time for many infectious parameters like Dengue, Leptospira, Mycoplasma pneumoniae, Chicken pox (varicella zoster) etc. As the equipment is fully automated, there is minimum human intervention during the tests and the variations in the test results are nullified.