As mentioned previously, HIER and EIER procedures can cause tissue sections to detach from the slides. There are other actions that may cause sections to detach from slides, such as improper fixation and processing. It is imperative to use a good quality, positive-charged slide. Many vendors offer ‘charged’ slides, but quality varies. Request samples of slides from vendors and compare which slides perform to your expectations. Using quality slides may be more expensive than slides required for general histology use, but loss of patient tissue, waste of expensive IHC reagents, and no charge repeats are even more costly.
A clean water bath must be used with positive-charged slides. Do not add gelatin or other adhesive additives, as they will counteract the positive charge on the slide.
Another area of concern is drying time for cut tissue sections. Histology laboratories are under turnaround time constraints, but proper drying is as important as positive-charged slides. Lift the slide slowly from the water bath allowing as much water as possible to drain from the slide. It may be preferred to stand slides on an absorbent towel while leaning against the water bath to further drain water from the slide. Placing the rack of slides in an area with a strong air current (fan, fume hood, etc.) for an extended amount of time before heat drying will improve section adherence. Much depends on the type of tissue you are working with. In general, bone marrow, skin, breast, and other hard or fatty tissues benefit from longer air drying. Overnight drying at room temperature or in a slide dryer set to 37° C is best, but not always the most practical for a clinical laboratory. Experiment with different drying protocols to see what works best in your laboratory.