Abstract
Changes in the relative sensitivity of reaction of oestrone, oestradiol, oestriol, and their monoglucuronides due to changes in reaction temperature and the acid and quinol concentrations of Kober's reagent have been investigated by means of an automated system. Similar investigations have been carried out with a number of standardized pregnancy urines. All measurements have been made with reference to an oestriol-16α(β-D-glucuronide) standard. These changes have been examined with trichloracetic acid and p-nitrophenol in Ittrich's reagent. The importance of the final acid concentration has also been examined. As a result of these investigations a modified scheme is suggested which gives maximal sensitivity to oestriol conjugates and minimal sensitivity to oestradiol conjugates, and may be calibrated by using an oestriol conjugate as a primary standard. The effect of varying the concentration of trichloracetic acid and p-nitrophenol in Ittrich's reagent has been examined under these modified conditions. More than 200 urines have been assayed by this method and the results compared with those obtained by the present automated procedure. The effect of dilution on many of these specimens has also been examined.