Construction, Figures of Merit and Testing of a Single-Cell Fluorescence Excitation Spectroscopy System

Author(s)

Laura S. Hill, University of South Carolina - Columbia
Tammi L. Richardson, University of South Carolina - Columbia
Louisa T.M. Profeta, University of South Carolina - Columbia
Timothy J. Shaw, University of South Carolina - ColumbiaFollow
Christopher J. Hintz, University of South Carolina - Columbia
Benjamin S. Twining, University of South Carolina - Columbia
Evelyn Lawrenz, University of South Carolina - Columbia
Micheal L. Myrick, University of South Carolina - ColumbiaFollow

Document Type

Article

Subject Area(s)

Chemistry, Oceanography

Abstract

Characterization of phytoplankton community composition is critical to understanding the ecology and biogeochemistry of the oceans. One approach to taxonomic characterization takes advantage of differing pigmentation between algal taxa and thus differences in fluorescence excitation spectra. Analyses of bulk water samples, however, may be confounded by interference from chromophoric dissolved organic matter or suspended particulate matter. Here, we describe an instrument that uses a laser trap based on a Nikon TE2000-U microscope to position individual phytoplankton cells for confocal fluorescence excitation spectroscopy, thus avoiding interference from the surrounding medium. Quantitative measurements of optical power give data in the form of photons emitted per photon of exposure for an individual phytoplankton cell. Residence times for individual phytoplankton in the instrument can be as long as several minutes with no substantial change in their fluorescence excitation spectra. The laser trap was found to generate two-photon fluorescence from the organisms so a modification was made to release the trap momentarily during data acquisition. Typical signal levels for an individual cell are in the range of 106 photons/s of fluorescence using a monochromated 75 W Xe arc lamp excitation source with a 2% transmission neutral density filter.

Digital Object Identifier (DOI)

https://doi.org/10.1063/1.3270251

Publication Info

Published in Review of Scientific Instruments, Volume 81, Issue 1, 2010, pages 013103-.

© Review of Scientific Instruments 2010, American Institute of Physics

APA Citation

Hill, L., Richardson, T., Profeta, L., Shaw, T., Hintz, C., Twining, B., Lawrenz, E., & Myrick, M. (2010). Construction, Figures of Merit and Testing of a Single-Cell Fluorescence Excitation Spectroscopy System. Review of Scientific Instruments, 81(1), 013103. https://doi.org/10.1063/1.3270251

Rights

© Review of Scientific Instruments 2010, American Institute of Physics