| 摘要 |
A process is disclosed for determining the concentration of an unbound species, e.g., thyroxine, cortisol, testosterone, or digoxin, in a liquid sample containing the species and protein. The sample is incubated with antibody specific to the species to be detected and a distinguishable analogue of the species, the antibody being initially separated from the sample by semipermeable membrane capable of excluding the passage of natural protein and antibody but allowing passage of the species and its analogue. The antibody and analogue are contained in semipermeable microcapsules. Free species in the sample permeates the membranes and competes for sites of attachment to the antibody with the analogue. The antibody is then separated from residual unbound species and unbound analogue. The amount of analogue present either in association with the antibody or in the remainder of the reaction system is indicative of the level of unbound species originally present in the sample. |
