We hear this question a lot. Some uninformed people actually think control solution is an “old technology”. We recently went out and bought 11 other meters and tested them, as you can see in our last post. All of the meters and test strips we purchased either came with control solution or had a control range on the side of the bottle. Why? What is control solution?
Control solution is a glucose solution that manufacturers produce with a set amount of glucose and red coloring to make it look like blood. They calibrate the control solution with the meter so you can only use control solution with its own brand of meter, just like test strips. There are usually 2-3 different levels of control solution. The only difference is that each one contains a different percentage of glucose.
Some people think control solution tests or calibrates the meter. That’s not true. What control solution does is test the test strip. All test strips have a plastic or paper base with very thin metal or carbon overlay and an enzyme. The blood or solution runs up the strip and mixes with the enzyme. The meter passes an electric charge through it and the resistance is what determines your blood sugar. The enzyme on the strip is very sensitive to heat, cold, moisture and direct sunlight. Performing a control test and comparing your result to the range on the side of the test strip bottle tells you whether the test strip is working correctly. Statistical analysis has shown that if one strip from a bottle is good then all the strips are good and conversely if one is bad then they’re all likely bad.
You should perform a control test the first time you open a bottle of strips and whenever you get a result that doesn’t seem right. Be very careful to match your control result to the correct range for the level of solution you used. The level is clearly marked on the bottle of control solution. If you get a result that’s outside the range, perform another control test right away.
The FDA only requires a meter’s result to be within 15% of the laboratory value 95% of the time. It’s always possible to get an outlier reading with any meter that you use. If your control test is outside the range twice then call your provider and give them the lot # of your bottle of test strips. They should exchange the test strips for you at no cost.
At Diathrive we send you control solution with every order so you can always have the peace of mind that your test strips are working correctly and giving you accurate results. It’s an extra cost but if you ever get a strange result late on a Friday or Saturday night you’ll be very glad you have control solution so you can know whether you really have a problem or whether your test strips have been damaged.