Low OD Value for Zero Standard in Competitive ELISA
Symptom
The zero standard (B0, representing maximum antibody binding without competing analyte) produces lower than expected optical density values, reducing overall assay sensitivity and dynamic range.
Common Causes
1Insufficient capture or detector antibody concentration
2Inadequate substrate incubation time
3Antibody binding affinity compromised due to suboptimal storage
4Substrate reagent expired or improperly stored
Solutions
1Optimize and increase antibody concentration through titration experiments
2Extend substrate incubation time to allow sufficient color development
3Verify antibody storage conditions and prepare fresh working solutions
4Check substrate expiration date and ensure proper storage at recommended temperature