Development and evaluation of rapid and semi-automated devices for the detection of toxic algae

Abstract

A commercially available PCR ELISA Dig Detection Kit was successfully adapted for the detection of the toxic dinoflagellate Alexandrium minutum by application of ribosomal 18S probes and sandwich hybridization. Furthermore, the assay showed the specificity of 10 additional probe sets for the toxic algal species. The total rRNA isolation protocol was improved and the hybridization procedure for the electrochemical detection of toxic algal species was described in detail and visualized for easy application by inexperienced users. Furthermore, locked nucleic acid probes were tested with known target sequences and the specificity and sensitivity was compared to signal formation of conventional molecular probes. The hybridization signals for both tested solid surface methods could not be enhanced and the conventional DNA probes showed equal or better results. A stand-alone, semi-automated system in combination with multiprobe chips was developed. A multiprobe chip with 16 gold electrodes was designed and adapted for the use in a sandwich hybridisation assay.