The nucleic acid stain Hoechst 33258 trihydrochloride (Ex/Em: 350/461nm) is frequently utilized as a cell-permeable nuclear counterstain that emits a blue fluorescence upon binding to dsDNA. Hoechst 33258 trihydrochloride is commonly employed in various studies related to cell counting, cell cycle analysis, and cell replication. It is particularly useful in identifying condensed nuclei in apoptotic cells, as well as in combination with BrdU staining for cell-cycle studies. Hoechst 33258 works similarly to Hoechst 33342 but is less cell permeable.
Hoechst dyes are also useful for monitoring cell viability by tracking changes in their emission spectra. As minor groove-binding DNA stains with AT selectivity, the Hoechst dyes are able to bind to all nucleic acids, but they show a greater fluorescence enhancement for AT-rich double-stranded DNA strands compared to GC-rich strands [1]. This property has been exploited to identify Q-bands in chromosomes, which are regions rich in AT base pairs that fluoresce brightly when stained with the quinacrine dye [2].
Fig. Fluorescence excitation and emission spectra of Hoechst 33258 bound to DNA
核酸染料Hoechst 33258 trihydrochloride(Ex/Em:350/461nm nm)通常作为可穿透细胞膜的核染色剂,在结合dsDNA后发出蓝色荧光,被广泛用于与细胞计数、细胞周期分析和细胞复制相关的各种研究中。它特别适用于鉴定凋亡细胞中的浓缩核,以及与BrdU染色结合用于细胞周期研究。Hoechst 33258的作用类似于Hoechst 33342,但其细胞穿透性较低。
Hoechst染料还可通过跟踪其发射光谱变化来监测细胞存活率。作为具有AT选择性的小沟结合DNA染料,Hoechst染料能够结合所有核酸,但相对于GC丰富的链,它们对富含AT的双链DNA链显示出更大的荧光增强作用[1]。这一特性已被用于鉴定染色体中富含AT碱基对的Q带区域,当用quinacrine染料染色时,这些区域会发出明亮的荧光[2]。
References:
[1]. Portugal J, Waring MJ. Assignment of DNA binding sites for 4′, 6-diamidine-2-phenylindole and bisbenzimide (Hoechst 33258). A comparative footprinting study. Biochimica et Biophysica Acta (BBA)-Gene Structure and Expression. 1988 Feb 28;949(2):158-68.
[2]. Weisblum B, Haenssler E. Fluorometric properties of the bibenzimidazole derivative Hoechst 33258, a fluorescent probe specific for AT concentration in chromosomal DNA. Chromosoma. 1974 Sep;46(3):255-60.