Glucose control solutions allow you to perform quality control checks to ensure that your Accu-Chek Instant, Accu-Chek InstantPlus, or Accu-Chek Instant DM system is working properly. Each glucose control solution contains a known amount of glucose. These solutions are used in exactly the same way as a drop of blood. If the control result is within the acceptable range printed on the vial of Accu-Chek Instant Glucose test strips, you know that your testing system is working properly.