5-foa Screening
5-foa Screening - Related Videos
09:53
Screening Assay for Oxidative Stress in a Feline Astrocyte Cell Line, G355-5
0 Views •
Cited by 11 •
2011
A screening method to detect oxidative cellular environments is to measure the oxidation of CM-H2DCFDA. Once oxidized within a cell, CM-H2DCFDA changes from non-fluorescent into a fluorescent compound. This change in fluorescence is measured by flow cytometry and indicates the number of cells in an oxidative environment.
01:04
5-Number Summary
0 Views •
2023
In a dataset, the 5-number summary includes the minimum data value, the data value of the first quartile, the median data value or data value of the second quartile, the data value of the third quartile, and the maximum data value. These 5 data values can be visualized as a box and whisker plot. In a box plot, the minimum and maximum data values represent the lower and upper whiskers in the graph, and the median is designated as the center of the box in the chart. The first quartile and third...
01:23
The 5 c's of Pricing
0 Views •
2024
The 5 Cs of pricing provide a comprehensive framework for strategic pricing decisions. They include: Company Objectives: The company's goals are pivotal in determining pricing. Whether the aim is to maximize profit, increase market share, or survive in a competitive market, it will directly influence the pricing strategy. Cost: It involves calculating the total cost of producing a product or service, including fixed and variable costs. Pricing must cover these costs and provide a reasonable...
08:12
High-throughput Screening for Protein-based Inheritance in S. cerevisiae
0 Views •
Cited by 2 •
2017
This protocol describes a high-throughput methodology to functionally screen for protein-based inheritance in S. cerevisiae.
09:44
High-throughput Screening for Chemical Modulators of Post-transcriptionally Regulated Genes
0 Views •
2015
Here we describe a cell-based reporter gene assay as a valuable tool to screen chemical libraries for compounds modulating post-transcriptional control mechanisms exerted through 3’ UTR.
FAQs
5-FOA screening functions as a counterselection rather than a direct positive selection for the desired replacement. The experiment links the outcome of interest to loss of functional URA3. Exposure to 5-FOA then removes URA3-positive cells from the population, enriching survivors whose genotype is compatible with the intended change. This logic makes metabolic sensitivity useful for genetic discrimination.
Resistance indicates that functional URA3 activity is absent or no longer present in the surviving cell, but it does not by itself identify which genetic event produced that state. In a replacement experiment, researchers interpret survival in relation to the intended locus or construct. The selection enriches candidates, while the specific genetic outcome remains the key biological result.
Unlike positive selection, which favors cells carrying a selectable trait, 5-FOA screening favors cells that have lost a particular function. That reversal is especially useful after a replacement or marker-removal step, because cells retaining URA3 are disadvantaged while ura3-deficient outcomes are enriched. The method therefore supports recovery of loss-of-function selection states without treating survival as evidence of one exact edit.
After a selectable marker has helped identify an earlier genetic manipulation, 5-FOA counterselection can favor cells in which the relevant URA3-dependent selection state is no longer retained. This supports removal of selectable markers while preserving the intended strain change. The approach is particularly useful when researchers need to construct strains with defined genetic changes through successive manipulation steps.
Researchers begin with cells carrying a URA3-dependent selection state and a planned genetic change, apply 5-FOA-containing medium, and retain cells that grow under counterselection. Surviving cells become candidates for the desired replacement, marker-loss event, or plasmid-loss outcome. Interpretation then connects survival with the intended genetic change rather than treating growth alone as complete characterization.
5-FOA screening can distinguish cells that have lost a plasmid-dependent URA3 state from cells that retain the associated function. Researchers apply the counterselection after the plasmid-loss step and use growth on 5-FOA medium as evidence consistent with curing. This provides a practical route to isolate strains free of an unwanted plasmid while retaining the desired cellular background.
The strategy depends on a metabolic pathway in which URA3 activity determines whether 5-FOA becomes toxic. It is therefore suited to organisms that produce uracil and support this URA3-linked response, with yeast providing the stated research context. In these systems, growth inhibition can be coupled directly to genotype, allowing genetic construction and selection within the same workflow.