Which observation would suggest the need to read a reagent strip color after the 2-minute mark should be ignored?

• A. Color develops before 2 minutes
• B. Color develops after 2 minutes
• C. Color matches pad
• D. Color read at 2 minutes exactly

Answer: (B)

Reading times matter for reagent-strip tests because each pad’s color change is calibrated to a specific, fixed window. If you wait longer than that window, the chemistry can continue to change beyond what the test is designed to measure, making the result unreliable. If the color appears only after the 2-minute mark, that result lies outside the validated read time, so you should ignore it and re-check at the correct time. Early color development within the window or color matching the pad at the designated read time can be considered valid within the test’s instructions, but post-window changes are not trusted.