Sample Pad and Conjugate Release
Poor sample absorption is often related to hydrophobic materials or insufficient treatment. Optimizing surfactant concentration and protein treatment can improve flow.
Incomplete conjugate release may be caused by particle aggregation, improper buffer composition or insufficient blocking of the conjugate pad.
Sensitivity and Stability
False positives and sensitivity loss should be investigated from gold conjugate blocking, buffer pH, humidity control and foil pouch sealing.
When the strip turns purple or gray during drying, colloidal gold particles may have aggregated due to excessive humidity, temperature or drying time.