Enumeration of Microalgae in Different Cell Growth Phases with Sandwich Hybridization Integrated with Nuclease Protection Assay

2207-2212Sandwich hybridization integrated with nuclease protection assay (NPA-SH), which takes advantage of high copy number of rRNA molecules in cells, has been developed to quantify microalgae. Seven microalgae in different cell growth phases were analysed by NPA-SH to find how the amounts of RNA had influence on enumeration of microalgae with NPA-SH. It was found that the calibration curves of NPA-SH from samples in different growth phases would influence the quantification results. Although the cell densities enumerated with the calibration curves from stable samples were higher than those by microscopy in the logarithmic growth phase, when rRNA greatly accumulated, it was very significant to detect samples from natural marine environments with NPA-SH. The results from this method can reflect the growth potentiality of microalgae, which will present the evidence for pre-warning of harmful algal blooms