SEPARATING THE TURBIDITY SPECTRA OF VESICLES FROM THE ABSORPTION-SPECTRA OF MEMBRANE PROBES AND OTHER CHROMOPHORES

The recording of the absorption spectra of membrane probes and other c hromophores is frequently difficult because of turbidity. While in hig hly scattering media such as tissues, the solution to the problem can be rather complex, in cell and vesicle suspensions it can be quite sim ple. In this work we aim to demonstrate that the ''blurred'' sum spect rum can be decomposed into the absorption and turbidity spectra using very well defined theoretical models rather than blind empirical proce dures and intuition. Basically, the methodology consists in the fittin g of a power law to an absorption - free segment of the total spectrum . The power parameter is related to the dimensions, refractive index a nd size polydispersity of the scattering particles. The proposed metho dology was applied to a polyene sterol probe in lipid vesicles (both u ni and multilamellar).