Loading...
Thumbnail Image
Item

Measurement Of Marine Picoplankton Cell-Size By Using A Cooled, Charge-Coupled Device Camera With Image-Analyzed Fluorescence Microscopy

Viles, CL
Sieracki, ME
Abstract
Accurate measurement of the biomass and size distribution of picoplankton cells (0.2 to 2.0-mu-m) is paramount in characterizing their contribution to the oceanic food web and global biogeochemical cycling. Image-analyzed fluorescence microscopy, usually based on video camera technology, allows detailed measurements of individual cells to be taken. The application of an imaging system employing a cooled, slow-scan charge-coupled device (CCD) camera to automated counting and sizing of individual picoplankton cells from natural marine samples is described. A slow-scan CCD-based camera was compared to a video camera and was superior for detecting and sizing very small, dim particles such as fluorochrome-stained bacteria. Several edge detection methods for accurately measuring picoplankton cells were evaluated. Standard fluorescent microspheres and a Sargasso Sea surface water picoplankton population were used in the evaluation. Global thresholding was inappropriate for these samples. Methods used previously in image analysis of nanoplankton cells (2 to 20-mu-m) also did not work well with the smaller picoplankton cells. A method combining an edge detector and an adaptive edge strength operator worked best for rapidly generating accurate cell sizes. A complete sample analysis of more than 1,000 cells averages about 50 min and yields size, shape, and fluorescence data for each cell. With this system, the entire size range of picoplankton can be counted and measured.
Description
Date
1992-02-01
Journal Title
Journal ISSN
Volume Title
Publisher
Download Dataset
Rights Holder
Usage License
Embargo
Research Projects
Organizational Units
Journal Issue
Keywords
Biological Sciences Peer-Reviewed Articles, Flow cytometry, bacteria
Citation
Advisor
Department
Virginia Institute of Marine Science
DOI
Embedded videos