TEMPORAL STABILITY OF ACETYLCHOLINESTERASE STAINING IN COLONIC AND RECTAL NEURAL TISSUE

Confirmation of the clinical diagnosis of Hirschsprung's disease on st andard rectal suction biopsy requires demonstration of aganglionosis i n 60 adequate serial sections of submucosa. Positive staining for acet ylcholinesterase (AChE), demonstrating an increase in nerve fibres wit hin the lamina propria, muscularis mucosae, and subjacent submucosa, i s a useful adjunctive test. In this study, sections of distal colonic muscularis propria and rectal mucosa were stained for AChE over a peri od of days following storage at 4 degrees C and at room temperature (1 5-20 degrees C). Positive staining of neural tissue was demonstrated i n specimens stored at 4 degrees C for up to 14 days, at which time the experiment was discontinued due to tissue autolysis. Positive stainin g of the myenteric plexus in colonic specimens stored at room temperat ure also continued until tissue dissolution became marked at 5 days. T his study has demonstrated stability of AChE staining of intestinal ne ural tissue in specimens stored at 4 degrees C for 14 days, which sugg ests that reliable staining for AChE should still be achievable if rec tal biopsies are taken in clinics/hospitals without access to staining facilities, provided that tissues are transferred (fresh and moist, a t 4 degrees C) to a reference laboratory for staining within several d ays of the biopsy procedure.