Detection of a Target Analyte Using a Bacterial Biosensor

Source: Barber, A. E., et al. Preparation and Application of a New Bacterial Biosensor for the Presumptive Detection of Gunshot Residue. J. Vis. Exp. (2019).This video demonstrates the detection of specific analytes using a bacterial biosensor. A bacterial culture carrying a plasmid with a red fluorescent protein (RFP) gene under an analyte-sensitive promoter is taken. After thoroughly wiping the test surface, a small section of the wipe is immersed in the culture and incubated. The analyte interaction with the promoter activates RFP expression, confirming the presence of the target analyte.