<prompt> Case finding in RNTCP is based onSputum cultureSputum microscopyX-ray chestPCR antibody detection  <response>: Sputum microscopy not only confirms the diagnosis, but also indicates the degree of infectivity and response to treatment - ParkRememberAt least 10000 104 bacilli should be present per ml of sputum for demonstration in direct smear on ZN stainingCulture can detect 10-100 bacilli per ml of sputum 