Method of tacrolimus extraction and quantification using aqueous detergents invention Site News | Monitor Keywords | Monitor Archive | Organizer | Account Info | The present invention relates to a method of extracting tacrolimus in a test blood sample to use in a tacrolimus quantification assay. The method of the present invention extracts tacrolimus in non-precipitating, non-denaturing aqueous environment, avoiding cumbersome manual pretreatment procedures or the use of organic solvents. The method of the present invention permits full automation of tacrolimus quantification assays. (end of abstract)[0002] Tacrolimus (also known as ProGraf.RTM. and FK506) is a macrolide lactone antibiotic with potent immunosuppresive properties isolated from the soil fungus Streptomyces tsukubaensis. Tacrolimus exhibits its immunosuppressive effect by inhibiting the calcineurin pathway (which ultimately inhibits T-cell proliferation) through the formation of a pentameric complex between tacrolimus, FK binding protein (FKBP), calmodulin, and calcineurins A and B (McKeon et al., Cell Vol. 66, pages 823-6 (1991)). Tacrolimus binds tightly to FKBP (Kd .about.0.4 nM), and is also known to bind to cyclophilin (Handschumacher et al., Science Vol. 226, pages 544-547 (1984)), albumins, and alpha-1-acid glycoprotein (Wong, Clinica Chimica Acta Vol. 313, pages 241-253 (2001). Tacrolimus, used in combination with other immunosuppressants, has gained broad acceptance for the treatment of tissue rejection following organ transplantation.
