Bis-MSB, a laser dye as a polarization probe for microheterogeneous media

Bis-MSB, a UV laser dye with an elongated rigid structure possesses good spectral characteristics, high molar extinction coefficient and a high fluorescence quantum yield. As it is similar to DPH structurally with desirable fluorescence probe characteristics, its applicability as fluorescence polarization probe for microheterogeneous medium has been investigated. It shows a high and constant polarization value comparable to that of DPH in all the organized media. It is completely non-polar and partitions almost completely into the lipid membrane. Being cheaper than DPH, it proves to be a promising candidate to be used as a polarization probe for lipid membranes.