Standard Curve Plateau at High Concentration Range (ELISA (Competitive))

Question

Accepted Answer

The standard curve reaches a plateau (flat response) at high standard concentrations with correspondingly low OD values, failing to show expected dose-response relationship in competitive ELISA format. Common causes: 1) Improper pipetting or dilution errors during standard curve preparation 2) Excessive non-specific binding interfering with competitive binding 3) Insufficient incubation time preventing equilibrium in competitive binding 4) Standard concentrations exceed the saturation point of the competitive assay Solutions: 1) Verify accurate pipetting and proper serial dilution of standard curve points 2) Check and reduce non-specific binding following background troubleshooting protocol 3) Extend incubation time to allow competitive binding to reach equilibrium 4) Adjust standard curve range to ensure high concentrations remain within dynamic range