1. Store test kits at 4-30˚C when not in use, and do not use the kits beyond the expiration date. 2. Remove microwell sealer slightly to prevent the powder from being released from the wells. 3. Avoid direct sunlight and direct blows during testing. 4. Do not re-use pipette tips, test strips or microwells. 5.This test method is just used for rapid screening purpose; if positive results are occurred, please verify them by a quantitative method. 6. If the sample extract is too alkaline (pH＞9) or acid (pH＜5), please adjust the pH value of the sample extract to be 6.0-8.0 by using NaOH or HCl (2.0mol/L) before dilution.