ABSTRACT
The two-step vacuum-microwave method simplifies and shortens histoprocessing. Acting margins are small so that fine-tuning is required. Temperature, vacuum and time should be in perfect balance. If not, a "cooking" effect (too high temperature) can easily be detected in the epidermis of skin biopsies. An adverse vacuum effect (when vacuum is obtained too abruptly) produces clefts, first observed where different tissues are contiguous. When time is set too shortly, impregnation will be insufficient, which is best seen in kidney tissue. The lessons from these observations may help future users to be troubleshooters while installing their unit.
Subject(s)
Microwaves , Paraffin Embedding/instrumentation , Paraffin Embedding/methods , Vacuum , Biopsy , Cervix Uteri/pathology , Evaluation Studies as Topic , Female , Humans , Kidney/pathology , Polyps/pathology , Skin/pathology , Temperature , Uterine Cervical Diseases/pathologyABSTRACT
When microwaving and vacuum is combined, decrease of boiling temperature can be exploited in the histoprocessing procedures allowing a completely novel approach for impregnating tissue with paraffin. We found that, if the pressure is sufficiently low in the paraffin step, no ethyl-alcohol step is necessary for the dehydration. In that case, the fixed tissue blocks can be directly placed into the isopropanol and, after that, in the hot paraffin, in which the final dehydration of the tissue takes place. The full histoprocessing procedure can thus be shortened into two steps only, with a processing time (for 72 biopsies) of a mere 40 min. Working completely without ethyl alcohol might be of interest for countries in which ethyl alcohol is difficult or expensive to obtain. We conclude that vacuum-microwave histoprocessing allows us to omit ethyl-alcohol dehydration and to replace xylene, resulting in a two-step 'green' (ecological) method.
