Described herein are systems and methods for distinguishing between a control solution and a blood sample. In one aspect, the methods include using a test strip in which multiple current transients are measured by a meter electrically connected to an electrochemical test strip. The current transients are used to determine if a sample is a blood sample or a control solution based on at least two characteristics. Further described herein are methods for calculating a discrimination criteria based upon at least two characteristics. Still further described herein are system for distinguishing between blood samples and control solutions.