Photina®, developed by Axxam researchers is an improved Ca²⁺ activated photoprotein optimized for the generation of precise Ca²⁺ mobilisation assays for High-Throughput Screening (HTS).

While the mechanism of action of Photina® is similar to other photoproteins, the total light release is greater and the reaction kinetic is slower - opening new opportunities for the application of flash luminescence assays in HTS. The inherent flash luminescence of Photina® offers several advantages compared to classical Ca²⁺ fluorescent dyes:

• low background levels result in a large signal to noise ratio
• Ca²⁺ concentrations can be measured at specific cellular sites
• tested compounds only require short incubation periods
• reaction kinetics can be followed.

Axxam scientists validated the expression and functionality of Photina® in various cell lines most frequently used in HTS, such as CHO, HEK293 and Jurkat cells.

While Photina® is very well-suited to measure GPCR activation, it also is ideal for any other cellular targets capable of increasing the intracellular Ca²⁺ concentration. Photina® has been validated for addressing other important drug discovery target classes, such as Ca²⁺ permeable ion channels or Na⁺/Ca²⁺ exchangers.

Photina® use has been validated in a range of flash luminescence plate readers - FLIPR3, FLIPR^TETRA, CyBi® Lumax, Lumilux, - and with different MTP formats (96, 384, 1536).

i-Photina® is an improved version of Photina® retaining the same mechanism of action and characteristics as Photina® but with an increased light release.

Axxam makes Photina® and i-Photina® available through licensing agreements. If you are interested in using Axxam's Photoproteins for your research or discovery, please contact us