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Techniques and Applications of Image Analysis in Microbiology

出版	Central Connecticut State University, 1989
URL	http://books.google.com.hk/books?id=hGQzOAAACAAJ&hl=&source=gbs_api

註釋In this study new applications and techniques were devised for the Omnimet image analysis system in microbiology. Two types of microbiological cultures were grown and studied using image analysis as a tool and as a comparison to other known techniques. Past uses of the Omnimet system were in metallurgy but those in microbiology were very limited. The two cultures used were bacteria and Euglena, a unicellular photosynthesizing protozoan. Five species of bacteria were studied for colony growth and size. Euglena culture growth was measured with image analysis and was compared with colorimetric (chlorophyll concentration) techniques. Five species of bacteria were representative of common groups. These species, grown in liquid cultures, were diluted and spread onto the surface of an agar culture medium in petri dishes. Sterile procedures were used. After incubation these cultures were measured by image analysis for colony numbers and size every hour, for a 36 hour period. These data were then plotted to compare colony number and growth in area, as a function of time. Euglene gracilie was grown in a pre-mixed nutritive medium, under Growlux bulbs. Every 12 hours the cultural growth rate was measured using two techniques, over a 108 hour period. Light absorbed by the culture was measured spectrophotometrically. This gave a relative absorbance value. By putting samples under the video microscope, image analysis allowed the determining of the actual cell count (per ml) in the culture. Cell count and absorbance values as a function of time were plotted and compared. The image analysis system was uniquely useful in getting the area measurements of the bacterial colonies, but for counting the number of colonies, it could be used only to a certain point. That point was when colonial boundaries began to overlap. Euglena cell counts by this method are very accurate up to the point in which there were so many cells that they began to overlap when observed microscopically. Both the bacterial colony count and the Euglena cell count drop-offs were depicted graphically as "curve peaks" in the data plots. This is a shortcoming of the system. When counting cells it cannot distinguish two overlapping cells from one cell and when counting colony it cannot distinguish between confluent conies and one colony. By circumventing this problem some very accurate and descriptive data were obtained of microbiological culture growth, for the curved peaks could be indicators of confluence. This method gives quantitative data whereas prior techniques yield only qualitative data. It also measured growth of bacterial colonies via number and area better than current techniques. Studies of other specific species can now be undertaken. These data can be used in a comparative study of each of the organisms grown. Image analysis will become a common tool in the laboratory. New image analysis systems with powerful software-based programs can overcome the shortcomings of the Omnimet System. Future trends in microbiology will surely involve these systems