I am working with polycaprolactone scaffolds and I would like to use in-cell western to determine the protein levels of bone markers. The issue is that even at these far red wavelengths used in ICW PCL seems to be somewhat autofluorescent and while it may not be an issue for highly expressed markers, it can certainly skew values for more scarce proteins. I tried staining with Sudan Black B to quench autofluorescence but it turns out that SBB itself lights up like a Christmas tree in 700-800nm. Has anyone had a similar issue and could recommend a dye or any other approach to deal with this?