Combination of ATP-bioluminescence and PNA probes allows rapid total counts and identification of specific microorganisms in mixed populations

We have combined ATP-dependent bioluminescence with a novel chemiluminescen t in situ hybridization (CISH) method using peroxidase-labeled peptide nucl eic acid (PNA) probes targeting species-specific rRNA sequences to provide total counts and subsequent identification of specific microorganisms. Both methods are applied to the same membrane filter following a short incubati on time and both methods provide results in the form of spots of light that are captured by the MicroStar (TM) detection system. Each spot of light re presents individual micro-colonies detected by either ATP bioluminescence o r PNA CISH. This new concept is particularly intended for in process and qu ality control of non-sterile products to rapidly provide total counts as we ll as presence/absence of specific indicators and/or pathogens in non-steri le, filterable samples. (C) 2001 Elsevier Science B.V. All rights reserved.