Moore J W, Hoare S A, Quinlan M K, Clark G M, Wang D Y
Department of Clinical Endocrinology, Imperial Cancer Research Fund, London, England.
J Steroid Biochem. 1987 Dec;28(6):677-81. doi: 10.1016/0022-4731(87)90397-9.
The percentage of non-protein-bound oestradiol in serum or other fluid measured by centrifugal ultrafiltration-dialysis was critically dependent on the supporting medium used to collect the ultrafiltrate. When either Whatman No. 1 filter paper discs, Whatman GF/D glass fibre discs or Celite were used, the ratios of 3H-steroid to [14C]glucose on the support were found to change with centrifugation time. This occurred when serum or protein-free filtrates were analysed and was eliminated when silanised Celite was employed as the support. It was also observed that when serum was analysed, the [3H]/[14C] ratio inside the cell increased linearly with centrifugation time and this was ascribed to the small changes in volume which occurred inside the cell as ultrafiltrate accumulated on the support. It was concluded that the correct time to sample the ratio of [3H]/[14C] inside was before centrifugation.
通过离心超滤-透析法测定的血清或其他体液中未结合蛋白的雌二醇百分比，严重依赖于用于收集超滤液的支持介质。当使用沃特曼1号滤纸圆盘、沃特曼GF/D玻璃纤维圆盘或硅藻土时，发现支持物上3H-类固醇与[14C]葡萄糖的比率会随离心时间而变化。在分析血清或无蛋白滤液时会出现这种情况，而当使用硅烷化硅藻土作为支持物时，这种情况就会消除。还观察到，在分析血清时，细胞内的[3H]/[14C]比率随离心时间呈线性增加，这归因于随着超滤液在支持物上积累，细胞内体积发生的微小变化。得出的结论是，正确的采样时间是在离心前，以获取细胞内[3H]/[14C]的比率。
