Chapter Cover Risk assessment for drug resistance Questions to ask Testing for TB disease Molecular assays for identification of M. tuberculosis complex Testing for drug resistance Growth-based (conventional, phenotypic) DST Molecular assays for identification of drug resistance When to use rapid molecular tests for drug resistance Communication with the TB laboratory When to order second-line drug testing False-positive results Other potential causes for false-positive results Investigating results of questionable validity Discordant results What to do if discordant test results are found Use of strain typing / molecular surveillance. Resources References Product Drug-Resistant Tuberculosis: A Survival Guide for Clinicians, 3rd edition / 2022 Updates