I am looking to do some imaging work directly from microscope slides. I know that it is important to make sure the slides are conductive and ITO coated slides are often mentioned. My questions then are, what surface resistivity is acceptable? My guess would be the lower the better, but there is a significant price difference depending on what value you go for. Also, who would you recommend as a supplier? Finally, do I need to prep the slides in any way prior to use?