Bacterial Colony Formation
Bacterial Colony Formation - Related Videos
06:44
Keratinocyte Colony Formation Assay: An In Vitro Assay to Assess the Ability of Keratinocytes to Grow into Colonies
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2023
In this video, we perform a clonogenic assay of keratinocytes harvested from adult mice to determine the ability of individual cells to proliferate and form colonies. This keratinocyte harvesting technique is useful for studying other downstream aspects of cutaneous chemical carcinogenesis and tumor promotion.
09:59
Community DNA Extraction from Bacterial Colonies
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2023
Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - The University of Arizona Demonstrating Author: Luisa Ikner Traditional methods of analysis for microbial communities within soils have usually involved either cultural assays utilizing dilution and plating methodology on selective and differential media or direct count assays. Direct counts offer information about the total number of bacteria present, but give no information about the number or diversity of populations present...
04:14
Establishing a Fungal-Bacterial Co-culture for Biofilm Formation
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2026
Source: Miquel Guennoc, C., et al. New Method for Qualitative Multi-scale Analysis of Bacterial Biofilms on Filamentous Fungal Colonies Using Confocal and Electron Microscopy. J. Vis. Exp. (2017)This video demonstrates the preparation of a fungal culture on treated cellophane membranes to support colony formation and radial growth. It then shows the cultivation and preparation of soil bacterial cells for interaction assays. Finally, it illustrates how bacterial cells adhere to the fungal colony...
11:17
A Semi-quantitative Approach to Assess Biofilm Formation Using Wrinkled Colony Development
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Cited by 32 •
2012
We provide a simple, semi-quantitative method to investigate biofilm formation in vitro. This method takes advantage of the Zeiss stemi 2000-C Dissecting Microscope (with camera attachment) to monitor both the timing and pattern of biofilm formation, as assessed by the development of wrinkled colonies.
03:54
Preparation of Bacterial Biofilm Colonies for Morphological Analysis
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2026
Source: Bucher, T., et. al., Methodologies for Studying B. subtilis Biofilms as a Model for Characterizing Small Molecule Biofilm Inhibitors. J. Vis. Exp.(2016)This video demonstrates the preparation of mature bacterial biofilm colonies for high-resolution imaging. It covers fixation, dehydration, mounting, and metal coating steps to preserve and visualize biofilm morphology.
FAQs
These conditions determine whether cells can divide repeatedly and remain viable on the solid surface. If one or more conditions are unsuitable, growth may be reduced or absent, producing fewer or smaller visible colonies. Comparing colony development under different conditions therefore helps researchers identify growth requirements and relate environmental variables to bacterial population changes.
Colony characteristics reflect how bacterial growth responds to its surroundings and may include differences in size, shape, color, and texture. Observing this combination of traits gives researchers descriptive information for comparing populations and supporting bacterial identification. Appearance is most useful when interpreted alongside growth conditions and other observations rather than treated as an isolated result.
Not necessarily. A visible colony may develop from one cell or from a small group of cells, so colony numbers represent viable starting units rather than an exact count of individual bacteria in every case. This distinction matters when researchers estimate viable cell numbers, compare samples, or interpret differences in population size from solid-surface growth.
The presence, absence, or relative size of colonies under selected nutrient, moisture, temperature, or oxygen conditions provides evidence about which conditions support growth. Researchers can compare outcomes across environments to determine whether a bacterium grows better under particular conditions. This approach links visible population development with the biological requirements of the organism.
A typical investigation places bacteria or a sample containing bacteria on a suitable solid surface, supplies appropriate nutrients and environmental conditions, and allows localized growth to become visible. Researchers then record colony number and characteristics such as size, shape, color, and texture. These observations can support isolation, identification, viable-cell estimation, and growth comparisons.
Researchers can compare colony development when bacteria encounter antibiotics with development under otherwise suitable conditions. Differences in colony presence, number, or growth characteristics indicate how the population responds to the tested condition. This application helps evaluate bacterial sensitivity or resistance-related outcomes while also connecting visible growth patterns with environmental effects.
In clinical testing, colony observations can support bacterial isolation and identification. Food-safety studies use the same population-level evidence to examine microbial presence, while biotechnology research can compare growth requirements and responses under controlled conditions. Across these fields, the method converts localized growth into observable information about viable bacteria and their behavior.