Table 13.2 Spectral properties of some lipid probes.

 
Fluorophore Labels for Lipid Probes
Spectral Property Pyrene DPH NBD BODIPY FL
Ex/Em (nm) * 340/376 360/430 470/530 507/513
QY (τ) † 0.6 (>100 nanoseconds)  0.8 (4–8 nanoseconds) 0.32 (5–10 nanoseconds)  0.9 (6 nanoseconds)
Concentration dependence Excimer emission (~470 nm) at high concentrations. Self-quenched at high concentrations. Self-quenched at high concentrations. Excimer emission (~620 nm) at high concentrations.
Environmental sensitivity Very sensitive to quenching by oxygen. Essentially nonfluorescent in water. Essentially nonfluorescent in water. Essentially nonfluorescent in water. Relatively insensitive. Strongly fluorescent in both aqueous and lipid environments.
* Typical fluorescence excitation and emission maxima for membrane-intercalated probes. † QY = fluorescence quantum yield; τ = fluorescence decay lifetime. Typical values for membrane-intercalated probes are listed. These values may show significant environment-dependent variations.