Standard Curve Plateau at High Concentration End

Symptom

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.

1. 1 Standard curve pipetting or serial dilution errors
2. 2 High non-specific background masking competitive inhibition
3. 3 Insufficient incubation time for competitive equilibrium to establish
4. 4 Antibody binding sites fully saturated at lower concentrations than expected

1. 1 Verify standard curve was pipetted and diluted correctly with proper mixing
2. 2 Check and reduce non-specific binding following background troubleshooting
3. 3 Increase incubation time to allow full competitive equilibrium
4. 4 Confirm antibody concentration is appropriate for competitive format