Fig. 1.

Optimization of OptiPrep™ gradient and detection of lipid raft marker, flotillin-1, in fractions obtained from Jurkat T cells. Cells were lysed and subjected to OptiPrep density gradient separation. The diagram on the left indicates the gradient region expected to contain rafts. Six hundred microliter fractions collected from top to bottom were analyzed by Western blot with an antibody recognizing the raft marker flotillin-1. Optimization of gradient consisted of pooling fractions 2, 3, and 4 into a single combined fraction 2. The Western blot analysis of all fractions shows a strong signal for flotillin-1 in combined fraction 2.