Linear discriminant analysis (LDA) of single-cell fluorescence excitation spectra (λem = 680 nm) for five species of marine phytoplankton was used to determine whether intra-species variation among single cells precluded discrimination among species. Single-cell spectra were recorded in an optical trap with a custom-built spectral fluorometer. For nitrogen (N)-replete cells, separation of all five species ( Emiliania huxleyi, a coccolithophore, Thalassiosira pseudonana, a diatom, Dunaliella tertiolecta, a chlorophyte, Amphidinium carterae, a dinoflagellate, and Rhodomonas salina, a cryptophyte) was possible using only a portion of the excitation spectra (570-610 nm). This wavelength region gave perfect classification of species with a minimum Fisher ratio of 62. For four species ( E. huxleyi, T. pseudonana, D. tertiolecta, and A. carterae), variations in fluorescence excitation spectra as cells were starved of N did not impact the classification process adversely within the chosen spectral window. R. salina cells grown with and without N showed significant differences in their fluorescence excitation spectra but could still be classified if a different spectral window (490-570 nm) was used. Overall, we conclude that intra-species variation among single-cell fluorescence excitation spectra does not preclude discrimination among species.
Vol. 7, Iss. 3 Virtual Journal for Biomedical Optics
LAURA S BRUCKMAN, TAMMI L RICHARDSON, JOSEPH A SWANSTROM, KATHLEEN A DONALDSON, MICHAEL ALLORA, TIMOTHY J SHAW, and MICHAEL L MYRICK, "Linear Discriminant Analysis of Single-Cell Fluorescence Excitation Spectra of Five Phytoplankton Species," Appl. Spectrosc. 66, 60-65 (2012)
References are not available for this paper.
OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.