First development and characterisation of polyclonal and monoclonal antibodies to the emerging fresh water toxin cylindrospermopsin

As increasing incidences in the occurrence of cylindrospermopsin (CYN) appear, in addition to further research on its toxicological nature, improved rapid methods to detect this toxin are required. Antibody based assays are renowned for their ability to provide rapid, portable, simple to use tests. As yet however there are no publications outlining how an antibody to CYN can be produced. A range of chemical approaches was investigated to synthesise CYN immunogens for antibody production but failed to generate a response. Finally, a modified Mannich reaction for immunogen synthesis was employed to couple the toxin to two carrier proteins. Both protein conjugates were successfully used to raise both polyclonal and monoclonal antibodies of high sensitivity to CYN. These antibodies were characterised employing competitive indirect ELISA and an optical biosensor assay. By ELISA the sensitivity achieved ranged from 27 to 131 pg/mL and by SPR 4.4 to 11.1 ng/mL thus demonstrating that the selection of immunoassay platform is important for the detection level required by the end user for their application. Low cross-reactivity to the much less toxic metabolite deoxyCYN was observed. This is the first reported production of antibodies to this toxin.

► First reported production of monoclonal and polyclonal antibodies to cylindrospermopsin.
► Only one of five different chemistries trialled was successful.
► Antibodies characterised in terms of sensitivity and shown to be capable of detecting picogramme levels of toxin.
► Antibodies characterised in terms of specificity and shown to have low cross-reactivity to deoxyCYN capable of detecting picogramme levels of toxin.
► Antibodies shown to function by ELISA and optical biosensor.