Optical methods of total internal reflection elepsometry, UV-vis and FT-IR spectroscopies were successfully adapted for detection of microcystin-LR either in purified form available commercially or naturally produced by algae. The method of TIRE was particularly promising because it was proved to be capable of detection of Microcystin LR in low concentrations down to 0.1ng/ml in direct immunoassay with specific monoclonal antibodies MC10E7. The above immune reaction is highly specific according to the results of the binding kinetics . This research may lead to a number of possible applications of the new technology of environmental control, and biomedicine.