Fluorescence quencher improves SCANSYSTEM for rapid bacterial detection

The optimized scansystem could detect contaminated platelet products within 24 h. However, the system's sensitivity was reduced by a high fluorescence background even in sterile samples, which led to the necessity of a well-trained staff for confirmation of microscope results.

A new protocol of the optimized scansystem with the addition of a fluorescence quencher was evaluated. Pool platelet concentrates contaminated with five transfusion-relevant bacterial strains were tested in a blind study.

In conjunction with new analysis software, the new quenching dye was able to reduce significantly unspecific background fluorescence. Sensitivity was best for Bacillus cereus and Escherichia coli (3 CFU/ml).

The application of a fluorescence quencher enables automated discrimination of positive and negative test results in 60% of all analysed samples.