A method for preparation of magnetizable cellulose and its application in radioimmunoassays for T-3 and T-4(1)

An easy adoptable technique has been developed to prepare magnetizable cellulose by the process of wet grinding of a mixture of iron oxide (magnetite) and cellulose in a stirred ball mill. Anti rabbit IgG was covalently coupled to this magnetizable cellulose. The immunosorbent thus prepared has been used in radioimmunoassays of T-3 and T-4 for the separation of bound and free antigens. The reliability of the above immunosorbent has been validated by studying assay parameters such as non-specific binding (NSB), maximum binding (B-0), CV etc. The single step process of wet grinding adopted here not only firmly binds magnetite and cellulose physically, but also lowers the size of the resulting magnetizable cellulose. The conventional method of preparation involves the coprecipitation of cellulose dissolved in cuprammonium hydroxide solution along with iron oxide, followed by extensive grinding and sieving of the iron oxide impregnated cellulose.