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

Question

Accepted Answer

The standard curve reaches a plateau at high analyte concentrations (low OD values in competitive format), showing no further decrease in signal despite increasing standard concentration. Common causes: 1) Standard curve pipetting or serial dilution errors 2) High non-specific background masking competitive inhibition 3) Insufficient incubation time for competitive equilibrium to establish 4) Antibody binding sites fully saturated at lower concentrations than expected Solutions: 1) Verify standard curve was pipetted and diluted correctly with proper mixing 2) Check and reduce non-specific binding following background troubleshooting 3) Increase incubation time to allow full competitive equilibrium 4) Confirm antibody concentration is appropriate for competitive format