The invention provides a reagent for detecting amyloid deposited in a biological tissue which can detect amyloid in vitro and in vivo with high sensitivity using a compound which has affinity with amyloid and is suppressed in toxicity such as mutagencity. The reagent for detecting amyloid deposited in a biological tissue comprises a compound represented by the following formula (1) or a salt thereof:
wherein A
1
, A
2
, A
3
and A
4
independently represent a carbon or nitrogen; R
1
is a radioactive halogen substituent; R
2
is a group selected from the group consisting of hydrogen, hydroxyl group, methoxy group, carboxyl group, amino group, N-methylamino group, N,N-dimethylamino group and cyano group; and m is an integer of 0 to 2, provided that at least one of A
1
, A
2
, A
3
and A
4
represents a carbon, and R
1
binds to a carbon represented by A
1
, A
2
, A
3
and A
4
.
本发明提供了一种用于检测
生物组织中沉积的淀粉样蛋白的试剂,该试剂使用与淀粉样蛋白具有亲和力且抑制毒性(如突变原性)的化合物,在体外和体内具有高灵敏度检测淀粉样蛋白。用于检测
生物组织中沉积的淀粉样蛋白的试剂包括由以下式(1)或其盐所表示的化合物:其中A1、A2、A3和A4独立地表示碳或氮;R1是放射性卤素取代基;R2是从氢、羟基、甲氧基、羧基、
氨基、N-甲基
氨基、N,N-二甲基
氨基和
氰基组成的群体中选择的一组基团;m是0到2的整数,前提是A1、A2、A3和A4中至少有一个表示碳,并且R1结合到由A1、A2、A3和A4表示的碳。