RT Journal Article SR Electronic T1 An investigation into the use of activated and non-activated papain in routine rhesus blood grouping JF Journal of Clinical Pathology JO J Clin Pathol FD BMJ Publishing Group Ltd and Association of Clinical Pathologists SP 503 OP 507 DO 10.1136/jcp.15.6.503 VO 15 IS 6 A1 Winter, G. C. B. A1 Wratten, B. E. YR 1962 UL http://jcp.bmj.com/content/15/6/503.abstract AB The activities of three commercial products of papain were compared as supplied and after activation, and when used in the enzyme-serum method for rhesus (D) grouping. Certain dangers in activation became apparent, and accurate determination of the proportions of papain to anti-D appeared more important than indiscriminate activation without reference to the initial enzyme activity. A technique for assessing these proportions is described.