The scientists exploited this molecular mechanism to construct a tumour - specific probe called POL - N (Protein transduction domain [PTD]- ODD - Luciferase - Near - infrared [NIR] dye) which contained: 1) the ODD core, 2) a PTD for intracellular delivery, 3) red - shifted luciferase, and 4)
a NIR fluorescent dye with peak emission around 700 nm.
Philip S. Low, PhD, from Purdue University, and colleagues developed a new fluorescent agent, OTL38, which is a conjugate of
NIR fluorescent dye and a folate analog that binds to folate receptor - alpha (FRα).