As previously stated, cholesterol content is relevant for the function of raft proteins and for sperm capacitation. To analyze if there was any relationship between these two events, we studied DRM proteins after incubating sperm under capacitating conditions. Most of the proteins did not change their respective immunofluorescence pattern upon incubation (data not shown). However, some proteins (IZUMO, CAV2, and FLOT2) and the ganglioside GM3 showed two different staining patterns in the capacitated population as shown in Figure 5 . In the case of CAV2 and GM3, some sperm displayed no signal; in contrast, FLOT2 and IZUMO showed a different staining pattern. Although these changes were observed in the capacitated population, in all cases they correlated with the loss of PNA staining, suggesting that the differential immunofluorescence patterns were due to the acrosome reaction and were not directly related to capacitation.