USE OF BUFFERED FORMALDEHYDE IN THE ENZYMATIC DIGESTION OF INFLAMED MUCOSA

Mucosal inflammation is associated with altered expression of cell mem brane molecules. Disaggregation of tissue for flow cytometry may intro duce artefactual changes. In an attempt to prevent the induction of ar tefacts, cells were fixed prior to isolation. The addition of 0.1% buf fered formaldehyde to the collagenase/dispase digestion of mucosal bio psy specimens from patients with inflammatory bowel disease enhances d etection of CD3, CD11b, CD16, CD63, and CD14. No significant effect wa s noted for CD19, CD67 or CD45. The expression of CD3, CD11b and CD45 correlated with the degree of endoscopic inflammation. Dilute buffered formaldehyde may be a useful adjunct to the enzymatic isolation of ce lls from mucosal specimens, by protecting surface antigens from digest ion or alterations in expression.