1. If the kit or sample is not returned to room temperature(20-25℃), the OD value will be lower than normal. 2. If the plate wells are dry during the washing process, the repeatability will be poor. Therefore, the next step should be carried out immediately after the plate is washed and patted dry. 3. Shake well before adding every reagent. 4. The stop solution is 2M sulfuric acid. Avoid contact with skin and mucous membranes. Immediately clean up any spills and wash the area with copious amounts of water. 5. Do not use reagents after the expiration date. Do not substitute reagents from any other manufacturer into the test kit. Do not combine reagents from other ELISA Kits with different Lot numbers. 6. The kit should be stored at a temperature of 2-8℃. Do not freeze the kit. Seal the unused plates into the original package and reseal them. The reagent is light-sensitive. Avoid exposure to light directly. 7. Signs of reagent deterioration. Any color in the reagent indicates that the reagent has deteriorated and should be discarded. 8. After adding substrate A and substrate B, generally the color will develop in 15 minutes. If the color is light, the reaction time can be extended to 20 minutes. On the contrary, the reaction time can be shortened. 9. When the concentrated washing solution and other reagent components crystallize, please heat (the temperature should not exceed 60 ℃) to dissolve before use.