Laser Excitation

The D-Count® analytical system is based on the principle of flow cytometry.

The labelled sample is automatically injected into the quartz flow cell of the D-Count® forming a narrow analysis stream that ensures micro-organisms pass the laser excitation beam one by one. The fluorescent signals from each cell are collected by sensitive detectors and analysed by digital data processing.

To ensure only labelled micro-organisms are detected and counted, D-Count employs similar signal discrimination techniques to those in the ChemScan RDI. These discriminants counteract product interference, which can affect other methods, and reject autofluorescent particles.