Abstract: The present invention discloses a method for rapid antimicrobial susceptibility testing to screen antibiotics in a few hours instead of days by conventional methods. This method can also be used to identify susceptible antibiotics to treat mycobacterial infection in a few days instead of the usual six to eight weeks. Fast screening of antibiotics is achieved by a short period of specimen incubation in different antibiotics embedded media to create differential bacterial counts. The differences of bacterial counts among antibiotics embedded media are subsequently amplified by DNA amplification methods for detection. Following DNA amplification, rapid quantitation and minimum inhibition concentration (MIC) determinations for a panel of antibiotics are achieved in less than one minute by fluorescence quantitation methods.