Methods used to determine the size of lipid rafts give different results. The conventional fluorescence resonance energy transfer (FRET) results could mean that there are no rafts (0 size) or that the density of the marker protein is too low to support intermolecular FRET (65). 5′NT, 5′ nucleotidase; FR, folate receptor; DAF, decay accelerating factor; PALP, placental alkaline phosphatase; HA, hemagglutinin; DMPE, 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine.
| Method | Cell | Marker | Size (nm) | No. of molecules | Ref. |
|---|---|---|---|---|---|
| Conventional | MDCK | GM1 | 0 | 0 | (37,65) |
| FRET | HeLa | 5′NT | |||
| NRK | FR | ||||
| FAO | CD59 | ||||
| Molecular cross-linking | BHK | DAF | >4 nm | 15 | (66) |
| Laser trap | BHK | PALP | ∼50 nm | 3000 | (67) |
| HA | |||||
| Depolarization | CHO | FR | <70 nm | 6000 | (68) |
| FRET | |||||
| Single-particle tracking | C3H | GM1 | ∼200 nm | 50,000 | (69) |
| Thy-1 | |||||
| Single dye tracing | HASM cells | DMPE | ∼700 nm | 600,000 | (70) |