Comparison of Flow Cytometry and Quantitative PCR Assays for Cyanobacteria Quantification

Abstract

Cyanobacterial blooms deteriorate water quality and some species produce cyanotoxins, posing a potential risk to human health. As such, rapid and accurate quantification of cyanobacteria is of growing interest worldwide. In this study, two conventional methods, flow cytometry (FCM) and real-time quantitative PCR (qPCR) were compared in terms of quantification of the total cyanobacteria species in a lab-cultured Microcystis aeruginosa and 10 tropical freshwater samples. Results showed that these two methods have high linearity and strong association (P<0.01), although qPCR has higher sensitivity for low concentrations, while FCM approach has much shorter analysis time for a comparable detection range. The 16S rRNA gene copies/cell ranged from 2.31 to 4.07 in natural freshwater samples. The results showed that the FCM method was preferred for routine cyanobacteria monitoring in the picoplankton range