Hello,

In my sandwich-type ELISA which is testing for small molecule inhibition of a protein-protein interaction, it seems that DMSO percentage and dilution protocol are important. I previously though that a lower DMSO percentage was always better. However, it seems that some compounds function better in the ELISA when they are put in with higher concentrations of DMSO. Is this difference in activity more likely a function of the DMSO in the ELISA plate helping compound activity or DMSO in the dilution tube aiding in solubility? Additionally, my ELISA dilution buffer contains a small amount of FBS and Tween-20. I adopted the buffer composition from an ELISA studying the inhibitory activity of proteins. Are these components of the buffer dispensable when studying the function of small molecules? Specifically, will doing away with any FBS or Tween-20 in my ELISA reduce error and make the assay more consistent? I feel that these components may interfere with small molecule solubility.

Thank you!