Figure 2.

Excitation and emission spectra of DsRed (solid lines), as well as emission spectra of rhodamine B (dotted line) and rhodamine 101 (dashed line). All emission spectra were taken from solutions with equal absorbances at the excitation wavelength, 551.5 nm. Emission was monitored at 583 nm for the DsRed excitation spectrum. DsRed was in an aqueous solution buffered with 10 mM Tris, pH 8.5; rhodamines were in ethanol.