Objectives: To isolate lipid rafts and determine their composition by using biochemical isolation in mice before, during and after the myelination process (5, 15 and 30 days old, respectively) and by using specific antibodies to confirm successful raft isolation. Furthermore, to compare the differences in myelination amongst aforementioned mice age groups in the brain stem of mice with the knock-out St8Sia1 gene with a defect in the synthesis of complex gangliosides. To determine how the lack thereof affects the organization of the myelin microdomains, and hence the maintenance of its integrity. Materials and methods: St8Sia1 KO mice that are 5, 15 and 30 days old were used in the study, with a deficiency in the synthesis of complex b – series gangliosides, as confirmed by genotyping using specific primers. Lipid rafts were isolated and the samples were fractionated using a yet unpublished protocol. Determination of protein concentration using Bradford method was needed for Western blot analysis. Proteins were separated in the sample by electrophoresis and then transferred to membranes. Using the primary and secondary antibodies, the expression of flotillin and transferrin, that is raft and non-lipid-raft markers were determined; and additionally myelin-associated glycoprotein (MAG) and myelin basic protein (MBP), markers of myelination. The membranes were visualized and imaged, and the results obtained were then subjected to densitometric analysis using Fiji software. Results: A statistically significant difference between all three age groups of mice was shown with flotillin and transferrin, while in MBP a significant difference was shown between 15 and 30 day old mice. However, the first two markers, unexpectedly, were found in all fractions, instead of the marker-specific fractions. Conclusion: Given the results of both markers, flotillin and transferrin, it seems likely that the raft isolation was incomplete and that the cell membranes were isolated instead.