Evidence for normal fibroblast cell membranes from individuals with Huntington's disease. A fluorescence probe study.

We used fluorescence spectroscopy in an attempt to identify differences in the fibroblast cell membranes from individuals with Huntington's disease (HD), compared to those from normal individuals. Eight pairs of age- and sex-matched fibroblast cultures were examined, each using four different fluorescent probes. To maximize the possibility of finding a difference between the normal and HD cells fluorescence probes were selected which localize in different regions of the membrane. Also, these probes differed in their sensitivity to the surrounding environment. Procedures were developed for labeling of the fibroblasts while they were still attached to glass coverslips. All fluorescence measurements were done on attached cells, which were all found to be viable by staining with trypan blue. Both low (5-7) and high (11-13) passage cultures were examined since earlier reports indicated that normal and HD fibroblasts could be distinguished at low passage using a fluorescence method. Using these 16 cultures, and multiple determinations of the fluorescence emission spectra, anisotropies, and lifetimes, we found no significant difference between normal and HD fibroblasts. If such a difference exists, it appears to be too small for use as a diagnostic indicator for Huntington's disease.