Ultrasensitive detection of coliforms by means of direct asymmetric PCR combined with disposable magnetic amperometric genosensors.

An extremely sensitive procedure for the isolation and detection of DNA from bacterial cell cultures is described. Direct asymmetric PCR amplified products from E. coli cultures are specifically detected, at a concentration level as low as 0.01 cfu mL(-1) (cfu, colony forming unit), using disposable magnetic DNA hybridization amperometric sensors with no need for culture preconcentration steps.