AkaLumine-HCl is a luminescent substrate of luciferase used for in vivo bioluminescence imaging. This product has a wavelength at the near-infrared region (670-680nm) that less susceptible to absorption by water and hemoglobin than luciferin. Therefore, it's possible to observe more deep inside the body.
An example of use is an artificial bioluminescence system called AkaBLI, developed by Dr. Atsushi Miyawaki and Dr. Satoshi Iwano, etc.
This method uses Akaluc as luciferase and AkaLumine-HCl as luciferin. It's possible to detect deep tissues noninvasively at the single-cell level and track cell activity over time in the same living animals.