腔肠素(55779-48-1,Coelenterazine) 是 apoaequorin 和 Renilla 荧光素酶的发光酶底物。Renilla 荧光素酶和底物 coelenterazine 被用作生物发光共振能量转移 (BRET) 中检测蛋白质-蛋白质相互作用的生物发光供体。腔肠素是一种超氧阴离子敏感化学发光钙离子探针，其也用于过氧亚硝酸盐的化学发光检测。荧光 : λex 429 nm, λem 466 nm。

腔肠素 （钙离子荧光探针）介绍：
腔肠素（Coelenterazine），是海肾荧光素酶（Rluc）和Gaussia荧光素酶（Gluc）等多种荧光素酶的作用底物，腔肠素也是水母发光蛋白的辅助因子，应用非常广泛，可用于检测活细胞中钙离子浓度，基因报告分析，BRET（生物发光共振能量转移）研究，ELISA，HTS，以及组织或细胞中ROS水平的化学发光检测。
Coelenterazine is a chemiluminescent luciferin probe that can be used to detect changes in calcium level and redox status.

腔肠素（Coelenterazine）是自然界中资源最丰富的天然荧光素，是绝大多数海洋发光生物（超过75%）的光能贮存分子。腔肠素可作为许多荧光素酶的底物，比如海肾荧光素酶（Rluc），Gaussia分泌型荧光素酶（Gluc），以及包括水母发光蛋白（aequorin）和薮枝螅发光蛋白（Obelia）在内的光蛋白（Photoproteins）。其发光原理是：以腔肠素为底物的荧光素酶在有分子氧的条件下，氧化腔肠素，产生高能量的中间产物，并在此过程中发射蓝色光，峰值发射波长约为450~480nm。与甲虫（或萤火虫）荧光素/荧光素酶系统不同，腔肠素/荧光素酶系统不需要三磷酸腺苷（ATP），因此更便于体内生物荧光的研究。因此，腔肠素常用作基于荧光分析的报告基因检测以及活体动物检测的发光底物。
腔肠素还能在酶非依赖性的氧化体系中自发荧光，细胞和组织内的超氧阴离子和过氧化亚硝基阴离子能够增强该自发光信号，因此其也可用来检测细胞/组织内活性氧（ROS）水平。 

腔肠素溶解性：溶于甲醇或者乙醇，不可溶于DMSO

腔肠素溶解特性：腔肠素及所有衍生物都溶于乙醇或者甲醇，切忌溶于DMSO。腔肠素的水溶性相当低，一般情况需用酸化的甲醇配制高浓度母液后再用水溶性缓冲液稀释到需要的工作液，现配现用。
腔肠素母液的配制：称取1mg腔肠素h粉末直接溶解于205μl酸化的甲醇溶液（100%甲醇中含有20μl/ml 3M或者6M HCl），配制成12 mM（~5mg/ml,5×）的腔肠素h储存液。-20℃（最好-80℃）分装避光保存，可能会有少量活性的丧失，但可保存4周。若存放在惰性气体中可长期保存。

HeLa cells produce coelenterazine chemiluminescence in vitro. (A) 5x10 5 HeLa cells were imaged sequentially, at 5 min intervals for 1 hour. (B) Quantification of HeLa (black) or buffer (white) coelenterazine chemiluminescence at each time point (n = 3). (C) 5x10 5 HeLa cells were imaged at 15 minutes following the addition of native coelenterazine ranging in concentration from 0 μmol/L to 100 μmol/L. (D) Quantification of HeLa (black) or buffer (white) coelenterazine chemiluminescence (n = 3). (E) A range of 500 to 1x10 6 HeLa cells were imaged 15 minutes following the addition of 10 μmol/L of native coelenterazine. (F) A range of 500 to 1x10 6 HeLa cells were imaged 1 minute following the addition of 1.07 mmol/L luciferin. (G) Correlation graph of coelenterazine chemiluminescent signal intensity (y-axis) versus the corresponding luciferase signal intensity (x-axis) for a given cell concentration. (Error bars represent the mean ± SEM.)

Coelenterazine produces luminescent signals following X-ray irradiation. (A) The chemiluminescent signal increases with increasing PpIX concentration and X-ray dose in a microplate containing only reagents and no cells.Data represent the mean ± SD (n = 4, *p < 0.05, **p < 0.01). (B) Luminescent signals recorded at different time points after X-ray irradiation. When the irradiation was subsequently repeated, the signal again increased and decayed over time. (C) A typical example of in vivo imaging of a mouse injected with coelenterazine before and after 3 Gy X-ray irradiation w/o 5-ALA treatment with tumor (arrowhead). (D) The average luminescence before and after 3XT, 3 Gy; ALA-3XT, 5-ALA treatment followed by 3 Gy irradiation with or without B16-BL6 tumor. Data represent the mean ± SD (n = 6).