Question: how well does α-Galactosylceramide dissolve in cell culture medium (containing PBMC cells and 10% serum, e.g. FBS)? Does it take a second for the lipid to load on lipoproteins present in the serum(or may be it is loaded on cell membranes?) or cultured cells have to be agitated (by mixing on a shaker) for some time for the loading to occur?
α-Galactosylceramide is widely used in cell culture experiments. People use it to stimulate NKT cell by adding the lipid (dissolved in DMSO+PBS) to PBMC, which are incubated in cell culture medium (normally RPMI-1640 + 10% serum). The concentration of DMSO in the cell culture medium is negligible, so I assume the lipid "dissolves" by loading to lipoproteins contained in the serum or by loading the cellular membranes. Or may be it just flows up and remains undissolved? Same question remains when people inject the lipid in vivo by IV or by intramuscular injections. Can one be sure that the lipid will be taken by lipoproteins, or may be by cell membranes?