Has anybody else observed the slight brown tinge that appears after borosilicate glass microscope slides are exposed to UV and ozone? Been trying to find articles, but nothing pops out at me. I'm just trying to find out how the surface chemistry of the glass changes. Whether the brown tinge is indicative of surface changes by nitrogen groups and whether the surface is oxidised further. I don't know how much energy is required to modify the surface of glass and whether a standard UV/ozone system comes even close to that. We clean our microscope slides pretty thoroughly, so I know its not due to contamination. Any articles people have seen around the traps about these subjects? Cheers all Dr Matt Davies Research Assistant Science & Technology Research Institute University of Hertfordshire College Lane HATFIELD AL10 9AB UK e : m.davies@herts.ac.uk t : +44 (0) 1707 28 61 74 f : +44 (0) 1707 28 41 85