Glucose Measurement in Zebrafish

Glucose measurements were performed using the Amplex Red Glucose Assay Kit (Invitrogen), according to manufacturer’s instructions. Larval extracts were prepared by sonication in 200 ul of cold PBS. Single 5-week old fish were first homogenized followed by sonication in 500 ul cold PBS. Extracts were spun for 15 min, 12000 rpm at 4 °C to remove debris, and the supernatant was used immediately or stored aliquoted at –80 °C until the assay was performed. Standard curves were generated with every assay. Graphs represent data combined from at least 2 independent experiments. Glucose values were normalized to protein concentration of the extract, and are reported relative to the average control value. To measure blood glucose levels in adult zebrafish, fish were anesthetized and blood collected essentially as described45 (link). Blood from the incision was directly applied to a Freestyle Lite glucose test strip, and glucose readings were obtained from the Freestyle Lite glucose meter (Abbott) as per manufacturer’s instructions.