活死染色试剂盒包含钙黄绿素-AM和碘化丙啶（PI）两种溶液,分别用于染色活细胞和死细胞。其中钙黄绿素-AM,即钙黄绿素的乙酰羟甲基酯,具有高度亲脂性和细胞膜透过性，能够穿过细胞膜被活细胞内的酯酶催化成钙黄绿素，从而发出明亮的绿色荧光。而核染色染料PI不能透过活细胞的细胞膜。但可以透过死细胞膜的变性区域来到达细胞核,并与细胞中的DNA双螺旋结构结合,从而发出红色荧光。

The LiveDeath Stain Kit contains two solutions, calcein -AM and propidium iodide (PI), for staining living and dead cells, respectively.Among them, calxanthin-AM, the acetyl hydroxymethyl ester of calxanthin-AM, is highly lipophilic and cell membrane permeable. It can cross the cell membrane and be catalyzed into calxanthin-AM by esterase in living cells, thus emitting bright green fluorescence.The nuclear dye PI does not penetrate the membrane of living cells.But it can pass through the denatured regions of the dead cell membrane to reach the nucleus, where it binds to the DNA double helix structure of the cell and fluoresces in red.