We actually just stared keeping a log for special stains, always for IHC. Our rule of thumb is that an IHC control slide cannot be oler than 6 months, although we go through most of them much faster. For the basic IHC, tonsil, fallopian tube etc we do not log the case information for IHC only specific antibody controls, HSV, HPV, etc. S. Paturzo TJHUH