SEMIAUTOMATED COLORIMETRIC AND ENZYMATIC ASSAYS FOR AQUATIC ORGANISMS USING MICROPLATE READERS

A semi-automated method for colorimetric and enzymatic assays using a microplate reader has been developed. This method enables simultaneous assays of an extended number of colorimetric measurements of protein concentration, and acetylcholinesterase activity in organisms. The correlation coefficient of the results obtained by conventional methods using a spectrophotometer and those obtained using a microplate reader was 0.98 for acetyl cholinesterase and 0.99 for protein determination. The variation coefficient for all assays was lower than 7%. The method is useful for fast determination of protein concentration and enzymatic measurements including inhibition studies and calculation of kinetic parameters. Three advantages are featured in comparison with classical methods. First is the possibility of hundreds of measurements within time periods ranging from minutes to hours. The second advantage is the low cost of the system and the third is the reduced volume of the system that enables the system to work on-board during a scientific cruise or to be decentralized. The limits of the methods and the possible developments are discussed.