Coelenterazine (Coelenteramine) is a luminescent enzyme substrate, used for monitoring reporter genes in BRET, ELISA and HTS techniques.

When monitoring various biological processes, coelenterazine (CTZ) can be catalyzed by luciferases, such as the sea pansy Renilla reniformis (Rluc) and the marine copepod Gaussia princeps (Gluc), which results in emission of blue light. In Gli36-Gluc- or Gli36-Rluc-expressing Gli36 cells, coelenterazine (8 礸/ml) shows a bioluminescence signal. [1] In RIN-5F, 4T1, HCT 116, HEK 293, 293FT, HeLa and INS-1 cells, coelenterazine can be used to assay superoxide anion concentrations. [2]

In 4T1-implanted mouse, Coelenterazine detects cancer-associated superoxide anion and used to evaluate the role of superoxide anion in cancer cell biology and its role in pathology. [2]

Cells are plated at a density of 5×10^4?cells per well into 24-well plates and grown to 80-100% confluency. Just before imaging, media are changed to a colorless solution containing (in mM): 2.7 KCl, 139 NaCl, 8.1 Na2HPO4, 0.7 H2O, 1.5 KH2PO4, 1.8 CaCl2, 1 MgCl2?and 5.5 d-glucose. Cells are preincubated for 15 min in the absence or presence of Pgp modulator, after which Coelenterazine (final concentration of 470 nM) is added directly to the cells. They are for reference only.

Mice are anesthetized with metofane or isoflurane before tail vein injection of Coelenterazine (4 μg/g) formulated from an ethanol stock diluted in sodium phosphate buffer (50 mM). Bioluminescence imaging is performed on the in vivo imaging system at 2, 6, 8, and 11 min after injection. Anesthesia is maintained during imaging by nose cone delivery of 2.5% isoflurane. After imaging, animals are killed by cervical dislocation; tumors are then harvested and weighed. They are for reference only.