Abstract
The problem of obtaining urinary and fecal samples free from intercontamination is a major obstacle to some studies of absorption and metabolism utilizing laboratory animals. In the course of a study of the efficiency of absorption of dietary thiamin by the rat, using a conventional apparatus, serious errors attributable to contamination of fecal samples with urine were encountered. Subsequently a glass separator of new design was constructed which has been shown to effect this separation with a high order of efficiency. The design and operation of this apparatus are described herewith.
The construction of the separator is outlined in Fig. 1. An essential feature is the flared funnel stem which serves to draw the urine away from the pathway of the feces, which fall directly into the feces tube. Glass-to-glass contact must be maintained between tip of funnel stem and the inside surface of the separator, so that urine may flow readily around the interior of the bulb and be drained off by the urine tube. Urine is prevented from falling directly into the feces tube by the glass cone which rests on three legs 1/2 in long. The feces tube is flared to 35 mm O.D. at the top, thereby being extended beneath the shoulder of separator bulb. The wire cage was constructed according to a design obtained from the nutrition Division, Food and Container Institute, Quartermaster Corps, Chicago, III.
The whole apparatus may be attached to a ring stand by means of a 6 in, iron ring to support weight of the funnel and cage, and by 2 clamps fastened to neck of separator and to the feces tube, respectively.
The efficiency of the separator was tested according to the following scheme.
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