Control solution is a specialized liquid that contains a known concentration of glucose, manufactured for use with a glucometer system. This solution is used to conduct a quality check, or verification, of the meter and test strip performance, ensuring they work correctly together. Although many users refer to this process as “calibration,” the test merely confirms the accuracy of the system against a predetermined standard.
Necessary Supplies and Pre-Test Checks
Before beginning, gather the glucometer, a new test strip, and the corresponding control solution, which is typically specific to the meter’s brand. Check the expiration dates printed on both the test strip container and the control solution vial. Control solution is often only reliable for three to six months after the bottle is first opened, so this secondary discard date should be noted. The test should be performed when the meter, strips, and solution are at room temperature, ideally between 68 and 77 degrees Fahrenheit (20–25 degrees Celsius). This temperature consistency prevents inaccurate readings caused by solution or strip degradation. If your system offers multiple control levels (e.g., Level 1 or Level 2), confirm the meter is set to the correct corresponding level for the solution you are using.
Step-by-Step Procedure for Control Solution Testing
Start by gently swirling the control solution vial a few times to ensure the components are mixed, avoiding excessive air bubbles. Insert a fresh test strip into the glucometer; this will power on the device and indicate it is ready to receive a sample. Some meters require you to manually select the control test mode before proceeding.
Once the meter is ready, dispense a small drop of the control solution onto a clean, non-absorbent surface, such as the cap of the control solution bottle. It is recommended to first squeeze out and wipe away a small drop to clear any dried solution from the bottle tip. The test strip is then brought to this drop, allowing the solution to be drawn into the sample port by capillary action.
The meter will begin its countdown, and the result will appear on the screen after the measurement time, typically within five seconds. Avoid touching the control solution bottle directly to the strip to prevent contamination of the vial. Once the result is displayed, properly discard the used test strip and immediately cap the control solution bottle tightly to preserve its integrity.
Understanding and Acting on Control Solution Results
After the test is complete, compare the numerical result displayed on the glucometer against the acceptable range provided by the manufacturer. This range is usually printed on the side of the test strip vial or included in the instructions for use. A successful test means the result falls within this range, confirming the meter and test strips are operating as intended. If the result falls outside the acceptable limits, the system has failed the quality check, indicating a potential problem with the meter, strip, or solution.
The immediate action is to repeat the test using a new test strip, ensuring all procedural steps, such as gently swirling the solution and checking expiration dates, were followed precisely. An out-of-range result may be caused by user error, an expired or contaminated test strip, or a control solution that was too hot or cold. If the second test still produces an unacceptable result, discontinue using the current test strip vial and meter. Contact the manufacturer’s customer support line for troubleshooting and guidance.