通过二（半胱氨酰）赖氨酸用￣（99m）Tc标记生物素

生物素（ｂｉｏｔｉｎ）和亲和素（ａｖｉｄｉｎ）具有很强的亲和力，这一特性可以被用于改进放免显像的预定位技术。本文阐述了利用一种新的含硫含氮配体Ｌ－Ｎ－Ｎ′－二（半胱氨酰）赖氨酸（ＢＣＬ）作为联接剂，用￣（９９ｍ）Ｔｃ标记生物素的方法。初步研究的结果表明，标记物具有较好的体内外稳定性，可以进一步用于抗肿瘤单抗预定位，再注射能与亲和素结合的放标生物素进行肿瘤显像。

LabelingBiotinwith Tc-99m via N,N'-Biscysteinyl-Lysine

A new biotin derivative was systhesized by conjugating N,N'-biscys-teinyl-lysine(BCL) to biocytin. The conditions of conjugation was studied. BCL-bio-cytine was labeled with Tc-99m. The labels was identified by TLC,GC and bonding with avidin. The biodistribution of the labels in normal mice was also investigat- ed. The stability of Tc-99m-BCL-biocytine both in vitro and in vivo suggested that the labels may be further used in pretargeting.