The method suggested by Wohlgemuth1 for the quantitative determination of fecal amylase does not yield dependable data when stools of a pronounced acid reaction are under examination. The principle of Wohlgemuth's method is the extraction of a weighed portion of feces with 1 per cent, sodium chlorid solution and the determination of the amylolytic activity of gradually decreasing volumes of this centrifugated extract, by means of a series of tubes in each of which 5 c.c. of 1 per cent. soluble starch is used as substrate. After twenty-four hours at 38 C. these tubes are treated with a solution of iodin and the extent of digestion determined colorimetrically.
In case the stools do not vary in reaction to any pronounced degree from the normal limits, the above procedure of Wohlgemuth is satisfactory for ordinary clinical purposes. However, when the dietary or metabolic régime of the patient is