Cholesterol metabolism. 4. The neutral fraction of the faecal lipid of rats fed diets with low and high cholesterol contents

Methods of Isolation and Estimation of Sterols

“…Riddell and Cook, 1955). Disadvantages are the time factor and that for fine resolutions the process must be repeated and preferably interposed with a chemical procedure (cf.…”

“…A useful adaptation of the Zaffaroni system for the separation of the weakly polar sterols is that of Neher and Wettstein (1952); this technique is used in this laboratory (e.g. Riddell and Cook, 1955) and is described in the Appendix. The Bush system has been used mainly for studying steroid hormones (Bush, 1954a).…”

“…A semi-quantitative measure of the amount present may be made by systems used in steroid and sterol analysis is given by Bush measuring the amount of color. Riddell and Cook, 1955). Values for the movement of the component spots are given either as R f values-the ratio of the band movement to the movement of the advancing front or better as R r values-the ratio between the distance run in a given time with respect to an accompanying sterol (e.g.…”