Hi everyone,

Any ideas how we could measure glucose levels in ZDF rats that exceed 33.33 mmol/L? We have a portable glucometer (One Touch Ultra Easy), which uses test strips and that seems accurate, but does not manage the higher levels.

Thanks. /Terry

Cayman and BioAssay Systems both have glucose assay kits that range from 1-250/300 mg/dL. However, these are plate based assay,and don't have the convenience of your test strips.
You might want to try putting in ~50/100 ul of blood/serum/plasma in a microvacutainer or even a plain ol' Eppendorf tube and mixing it 1:2 or 1:4 with buffer to dilute it, before you add the drop to a test strip.

you can analyze the serum glucose level on any biochemical analzer withdilution to get the values in range (sensitivity of machine). or else you can do one more tricky idea such as collect the blood in tube and mix in dilution of 1:1 or 1:2 with heparinized saline as you required to get the values with your confidence or your glucometer's sensitivity.

Let me know if it doesn't solve you problem

Chintan

Did either of these suggestions work for you? I'm in the same situation. I work with both streptozotocin-induced and ZDF diabetic rats. We also have a OneTouch Ultra glucometer. The range tops out at 33.33mmol/L (600 mg/dl), but we have a need to measure higher than this for glucose tolerance tests. I have tried diluting whole blood with saline in a 1:1 ratio, but it does not appear to dilute linearly. It is pretty inconsistent, but ranges from 1/3 to 1/4 of the concentration of whole blood (measured using nondiabetic rats, normally around 100mg/dl, unfasted.) I have also tried using plasma, but this is not really a feasible option because the rats would have to be anesthetized, which affects their blood glucose drastically. Besides, diluting plasma had the same result.
I believe this glucometer uses some variation of the glucose oxidase method, but I'm not certain and it has been difficult for me to find the exact method that it uses. I suspect the idea of diluting blood is complicated by proteins and intracellular glucose in RBCs or other cells. If anyone can suggest a different glucometer (most have a max range of 600mg/dl) or an alternate method, I would be greatly in your debt. Thank you!