[Complete elimination of xylene in practice of a histology laboratory].

In the 1970s xylene was proven to be toxic to histology laboratory staff and its substitutes became available, many of which were no less so. Isopropanol (2-propanol) alone or mixed with molten paraffin is a technically suitable and cost-effective xylene substitute for tissue processing over many years. In this study, we demonstrate that mixtures of 5:1 and 2:1 isopropanol and mineral oil, followed by undiluted mineral oil (at 50 degrees C), are a gentler, safer and cheaper substitute than xylene. This tissue processing is now the method of choice in 3 Russian histology laboratories. The tissues processed in this fashion are suitable for many special procedures. The use of a dishwasher soap aqueous solution at 90 degrees C to dewax sections before staining and oven drying prior to coverslipping will eliminate xylene from the staining process. Tissue processors retorts, conduits, and other tools may be dewaxed with a 2% solution of a strong glassware laboratory detergent. These 4 methodologies make a histology laboratory free from xylene but, due to the natural resistance to changes, many histotechicians will be reluctant to adopt them, if they think that their technical expertise could be jeopardized. The only way these changes will succeed is if the pathologists who determine the use of these methods in histology laboratories.