1. Prepare all reagents, samples and standards;
2. Add 100uL standard or sample to each well. Incubate 2 hours at 37℃;
3. Aspirate and add 100uL prepared Detection Reagent A. Incubate 1 hour at 37℃;
4. Aspirate and wash 5 times;
5. Add 90uL Substrate Solution. Incubate 10-20 minutes at 37℃;
6. Add 50uL Stop Solution. Read at 450nm immediately.