Why are there so many little black spots in my Western blot background?

1. The part on the membrane is non-specifically bound to the primary or secondary antibody, and the configured blocking solution may not completely dissolve, and the particles are adhere to the membrane, resulting in the formation of black spots on the membrane when the luminescence occurs. The closed milk must be pure, and when the blocking solution is configured, ensure that the solute is completely dissolved, and it is best to rest it after the configuration.  

2. There may be impurities in the antibody, filter the blocking reagent before use.  

3. There are aggregates in the secondary antibody. Filter the secondary antibody reagents to remove aggregates.  

4. Non-specific binding of antibodies to blocking reagents, filter blocking solution or select other types of blocking solution