Insulin Tolerance Test

Materials (Bring Downstairs)

• Glucometer - AccuChek Advantage
• Glucose Test Strips - AccuChek Comfort Curve. Order these through Materiels Service by calling 936-6077 and ordering product 2535. For information see [here]
• Scale
• Beaker for weighing mice
• Syringes
• 0.1 U/mL humulin in PBS (make as 10uL of 100 U/mL in 10 mL, sterile filtered). This will correspond to 1 U/kg injections. This may need to be adjusted depending on the insulin sensitivity of the mice. This is diluted from Humulin R-100 and is purchased through the veterinary staff.
• Timer

Protocol

• Remove food from mice for about 6h. Add do not feed tag to cages, or move cage to procedure room.
• Typically starve the mice at 9AM and aim to start injections at 3 PM
• Weigh mice, mark tails if necessary and take fasting glucose measurement via a tail clip.
• Prepare insulin syringes with 10 uL per g mouse weight (ie for a 30g mouse, 300 uL).
• At approximately 1 min intervals, inject appropriate amount of insulin into interperitoneal cavity of the mouse.
  • Immobilize mouse and restrain tail with one hand
  • Aim needle between the midline and the hip bone
  • Insert syringe (do not inject) into cavity
  • Eject syringe.
• At desired intervals (normally 15, 30, 45, 60, 75, 90, 105 and 120 min), take blood glucose measurements from tail vein. If needed re-snip the tail vein. When measuring glucose just lift the tail of the mouse, while leaving it in the cage, rather than removing and restraining the mouse.
• Analyse data by both % change from fasting glucose and absolute values