Histochemical detection of GM1 ganglioside using cholera toxin-B subunit. Evaluation of critical factors optimal for in situ detection with special emphasis to acetone pre-extraction
Abstract
A comparison of histochemical detection of GM1 ganglioside in cryostat sections using cholera toxin B-subunit after fixation with 4% formaldehyde and dry acetone gave tissue-dependant results. In the liver neither pretreatment showed detectable differences relative to GM1 reaction products, while studies in the brain showed the superiority of acetone preextraction (followed by formaldehyde), which yielded sharper images compared to the diffuse, blurred staining pattern associated with formaldehyde.
Thus, anhydrous conditions (dry tissue samples and anhydrous acetone) are crucial factors for optimal in situ ganglioside detection using acetone pretreatment. This insures effective physical fixation (precipitation, prevention of in situ diffusion),, especially in tissues rich in polar lipids and removal of cholesterol, which can act as a hydrophobic blocking barrier.