Correction

BIOPHYSICS. For the article “Simultaneous two-photon excitation of distinct labels for dual-color fluorescence crosscorrelation analysis” by Katrin G. Heinze, Andre Koltermann, and Petra Schwille, which appeared in number 19, September 12, 2000, of Proc. Natl. Acad. Sci. USA (97, 10377–10382), the authors note the following correction. In Fig. 3 (wavelength dependence of emission), the legends for the dyes Texas red and Rhodamine green were accidentally permuted. The essence of the article is not altered.