We detected autofluorescence emission from all of the Candida species in all growth media. However, there were no significant differences between species grown in YPD and RPMI when looking at the number of spectral factors detected, the shape of the spectral factor, their wavelength of maximum emission, or their relative abundances throughout the fungal cells. In human serum, however, samples exhibited differences in autofluorescence depending on the species. Because this condition most closely matches the nature of clinical samples, we focused our further investigations on autofluorescence components for Candida in human serum. The multivariate curve resolution (MCR) analysis resulted in two different emission factors for all species [Figs. 1(a)–1(c)]. Factor 1’s spectral shape and peak (550 nm) are very similar across all species, leading to the idea that the three species investigated share a set of common autofluorescent molecules that emit around 550 nm. In contrast, factor 2’s spectral shape and peak (600 to 650 nm) vary depending on which species are being observed [Figs. 1(a)–1(c)]. For example, C. albicans factor 2 peak is found at 600 nm, C. parapsilosis factor 2 peak is found at 650 nm, and, interestingly, C. glabrata factor 2 peak is broad (the peak encompasses 600 to 650 nm). When we examined autofluorescent emission from human serum alone, it did not match either factor found in the Candida samples and is not an obvious linear combination of the two factors [Fig. 1(d)].