Purpose: The glucose tolerance test measures the clearance of an intraperitoneally injected glucose load from the body. It is used to detect disturbances in glucose metabolism that can be linked to human conditions such as diabetes or metabolic syndrome. Animals are fasted for approximately 16 to 18 hours, fasted blood glucose levels are determined before a solution of glucose is administered by intra-peritoneal (IP) injection. Subsequently, the blood glucose level is measured at different time points during the following 2 hours.
Scope:
Minimum number of mutants: 7 mice for each sex
Age at test: 13 weeks
Sex: Both (sexually dimorphic)
Materials:
One Touch® Ultra2 glucose meter
Stainless steel disposable scalpels
Balance
Timer
Glucose solution 20% (0.9 NaCl)
Gauge needle (25 G 5/8)
Syringe 1 ml
One Touch® Ultra Test Strips or Generic Brand
Gauze and alcohol (70%)
Topical anesthetic cream (optional)
Mouse restraining device (optional)
Quality Control
Calibrate the glucometers each day.
Weighing of mice should be completed before the pre-bleed is taken.
Mice should only be housed in a duplex with animals of the same sex.
Set-up
Fast mice overnight for 16 hours by transferring mice to clean cages with no food. Ensure that they have access to drinking water at all times
Prepare an experiment record sheet, lab mat work space, syringe, gauze, alcohol, glucose strips, glucose meters and freshly made 20% glucose solution.
Make sure that glucose meter and strips are the same code before starting.
Stick one strip into the glucose meter all the way.
Obtain the Control Solution; check that date of use is before the discard date. If not, discard and acquire a new control. Write the discard date on the control bottle three months from the date opened.
Shake the control bottle before using and put one drop of the control on the glucose strip in the glucose meter. Make sure control solution fills up the strip and touches the base.
Once reading appears compare control reading to the control range on the test strip bottle. Press the right arrow button to log the reading into the glucometer, L1 will appear on the top of the screen, and then press the power button on the side of the meter.
Record the control reading for internal purposes.
Weighing and separating mice
Start weighing the mice in numerical order so that the mice weighed last have some time to calm down before getting a baseline reading.
Grab a mouse out of the cage with deliberate movements trying to reduce any chasing.
Have the cage close enough to the scale that mouse is not suspended by its tail for more than 3 seconds.
Place the mouse on the scale and record its weight. Place the mouse in a duplex by side by itself. The cage should be clean or the clean cage from fasting making sure the mouse has access to water. The mice should be separated so that they are in numerical order. No mouse should be in a duplex with a mouse of the opposite sex.
Once weighing is complete move cages to IPGTT room nicely on a cart. Place cages in numerical order nicely, avoiding any shaking or bumping of the cage.
Procedure
Calculate and record the volume of 20% glucose solution required (2g of glucose/kg body mass) for IP injection as follows: volume of IP glucose injection (µl) = 10 x body weight (g).
Set the test strip in the glucose meter, part of the way. If left in all the way, the meter tends to turn off before blood is administered.
Recap the strip container every time after obtaining a strip. Do not use strips that have been left open to air for extended periods of time.
Clean tail with gauze soaked with 70% alcohol, then dry tail with dry gauze. Make sure tail is dry.
Score the tip of the tail using a fresh or sterilized scalpel blade, only a millimeter or two is needed.
Push test strip all the way into the glucose meter, drop indicator will show up.
Milk the tail and discard the first small drop of blood by dabbing on lab mat.
A small drop of blood (
- Badges
- Science topic
- Similar topics
- Biological Science
- Bioscience
- Biotechnology