Dowsett M, Mansfield M D, Griggs D J, Jeffcoate S L
J Steroid Biochem. 1984 Sep;21(3):343-5. doi: 10.1016/0022-4731(84)90290-5.
The validity of the centrifugal ultrafiltration-dialysis method in the measurement of the percentage of oestradiol and testosterone which is not bound to protein (free) in human serum was assessed. In an initial validation, the values of % free steroid obtained for oestradiol and testosterone in protein-free ultrafiltrates of human serum were higher than expected. Filter paper discs used in the system were shown to adsorb [3H]oestradiol from protein-free solution. Their replacement with glass-fibre discs, which did not adsorb oestradiol, decreased but did not eliminate the discrepancy between observed and expected results for % free oestradiol in ultrafiltrates. The use of polyethylene rather than polypropylene vials then reduced the discrepancy to insignificant levels. The estimates for % free oestradiol in serum were reduced by these modifications.
评估了离心超滤-透析法在测定人血清中未与蛋白质结合（游离）的雌二醇和睾酮百分比方面的有效性。在初步验证中，人血清无蛋白超滤液中雌二醇和睾酮的游离类固醇百分比值高于预期。该系统中使用的滤纸圆盘被证明会从无蛋白溶液中吸附[³H]雌二醇。用不吸附雌二醇的玻璃纤维圆盘替代滤纸圆盘，减少了但并未消除超滤液中游离雌二醇观察值与预期值之间的差异。随后使用聚乙烯瓶而非聚丙烯瓶将差异降低到微不足道的水平。这些改进措施降低了血清中游离雌二醇百分比的估计值。
