FIREFLY ASSAY OF ATP FROM FRESH-WATER ZOOPLANKTON - COMPARISON OF EXTRACTION METHODS

Investigations were conducted to compare the efficiency of adenosine triphosphate (ATP) extraction from freshwater zooplankton species (Skistodiaptomus oregonensis, Tropocyclops prasinus mexicanus, Daphnia magna, and Bosmina longirostris) using DMSO and cold H2SO4 extraction procedures. DMSO was found to extract more ATP (particularly in copepod species) while cold H2SO4 provided more consistent results. Homogenization by grinding samples during extraction was shown to be a very important step. Juvenile and adult specimens of D. magna were extracted. Adults gave higher ATP values. The necessity for a 24-h acclimation period was tested. Although acclimation appeared to provide more consistent results, no marked lowering of ATP level in organisms was registered without acclimation. No unique method was found to be optimal for all studied species.