固定对用TUNEL技术原位检测细胞凋亡的影响

Effect of fixation on apoptotic cell detection with the TUNEL technique

用TUNEL技术原位检测凋亡细胞对组织的处理方法较为敏感。本研究采用灌注固定及浸润固定处理的石蜡切片来比较固定处理对细胞凋亡检测的影响。结果显示成年大白兔睾丸 (正常及输精管结扎术后的 )内凋亡的生精细胞 ,在用 4%的多聚甲醛先灌注固定然后浸润固定处理后可以检测到 ,仅用Bouin液浸润固定整个器官 2 4小时的方法检测不到凋亡细胞。尽管其原因不清楚 ,但该结果可能提示TUNEL法对凋亡细胞检测的敏感度高度依赖于固定处理情况 ,故对凋亡细胞的阴性检测结果的解释应慎重。

The TUNEL technique for in situ apoptotic cell detection is sensitive to tissue processing. Perfusion- and immersion-fixed paraffin sections were used in the present study to compare the effect of fixation on such detection. The results showed that apoptotic germ cells in the adult rabbit testis (normal and vasectomized) were detectable when the organ was first perfusion-fixed and then immersion-fixed in paraformaldehyde, not, however, when it was only immersion-fixed in Bouin's solution for 24 hours. Although the discrepancy was not clearly understood the results might imply that the sensitivity of the TUNEL method was highly dependent on fixation and therefore interpretation for a negative finding of apoptotic cells should be cautionary.