Coral Jane Fung Shek, a graduate student at Johns Hopkins University, explored the efficacy and accurary of using dynamic imaging particle analysis, also knowns as imaging flow microscopy, for conducting quantitative morphological analysis of algae, and the accuracy of this method for color sensitivity and algal cell counting.
From the Fluid Imaging Technologies Lab: Chlorella vulgaris captured by the FlowCam at 20X
In her thesis "Dynamic Imaging Particle Analysis For Quantitative Morphological Analysis and Cell Counting" (2015), Fung Shek investigated and quantified morphological differences in algae exposed to different growth conditions, tested the color sensitivity of the FlowCam, and compared monoculture and polyculture cell counting capabilities of the FlowCam with the hemocytometer and optical density readings using the UV/Vis Spectrophotometer.
Fung Shek used the FlowCam and its associated analytical software VisualSpreadsheet to measure and analyze the geodesic length, area, circularity, and equivalent spherical diameter of algal cells to enable comparison of cell size, shape, and growth rate of over 25 strains of algae subjected to various growth conditions.
Average Red Green and Blue (RGB) values of three different algae cultures were used to test color channel sensitivity of the FlowCam. Fung Shek found that RGB values measured by the FlowCam were shown to be an effective indicator of the color difference between cultures.
The cell quantification capability of the FlowCam was compared to the hemocytometer and optical density measurements from a UV/Vis Spectrophotometer. The monoculture algal cell quantification results from the FlowCam and hemocytometry showed a high correlation value with minor variability. The optical density readings from th UV/Vis Spectrophotometer and the FlowCam also showed correlation, however the results were more variable, likely due to inherent variability of the spectrophotometer.
The FlowCam was able to quantify both species, Synechoccus elongatus and Cryptococcus curvatus, within a polyculture. Due to the small size of S. elongatus, the hemocytometer was unable to detect and count this algae species. The FlowCam and hemocytometer quantification results for S. elongatus were significantly similar.
Additionally, Fung Shek determined that the use of chlorophyll-detecting lasers and analytical filters in VisualSpreadsheet would have aided in the differentiation of C. sorokiniana cells from bacteria in unsterilized, active wastewater.
Read more about Fung Shek's research→ Access Fung Shek's full thesis here.
Fung Shek was the recipient of the 2015 Fluid Imaging Technologies, Inc. Student Research Grant.
Learn more about using the FlowCam for conducting quantitative and qualitative morphological algae analyses.
Fung Shek, C.J., Dynamic Imaging Particle Analysis for Quantative Morphological Analysis and Cell Counting [master's thesis]. [Baltimore (MD)]: Johns Hopkins University; 2015. 85 p.