Spectrophotometric Method to Estimate Glycogen Levels in the Model Nematode Caenorhabditis elegans
The model nematode Caenorhabditis elegans is widely used in studies on metabolic regulation and aging processes, in developmental and cell biology, neurobiology and genetics. Recent studies have shown the crucial role of glycogen, the glucose polymer, in stress resistance, energy maintenance and aging of organisms. Currently, the main methods for determining glycogen in the C. elegans nematode are iodine staining, enzyme analysis, and Raman microspectroscopy, described in 2019 by A. Cher-kas. The proposed spectrophotometric method allows us to quantify glycogen levels, in contrast to those used in modern practice. The nematode was grown on NGM agar seeded with E. coli as a food source for 7 days in a thermostat at 20±20C. Then, it was washed with M9 buffer and separated from bacteria by centrifugation for 10 min at 9 000 g. The samples were placed in an ice bath and nematodes were counted in each sample at x 10 microscope magnification. The glycogen concentration was determined spectrophotometrically. This value is average for different stages of the nematode development and amounts to 0.001821 ± 0.000009 mkg.