Modified Cytosine Detection
Modified Cytosine Detection - Related Videos
07:13
Detection of Modified Forms of Cytosine Using Sensitive Immunohistochemistry
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Cited by 8 •
2016
Herein we describe a sensitive immunochemical method for mapping the spatial distribution of 5mC oxidation derivatives based on the use of peroxidase-conjugated secondary antibodies and tyramide signal amplification.
03:01
Detection of Target Enzyme Expression in Genetically Modified Bacterial Cells
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2025
Source: Kim, H. et. al., Multi-enzyme Screening Using a High-throughput Genetic Enzyme Screening System. J. Vis. Exp. (2016)This video demonstrates a genetic screening method to detect enzyme expression using metagenomic fosmid libraries and chromogenic substrates. Flow cytometry identifies and isolates single cells producing colored products, enabling high-throughput selection of active enzyme-expressing cells.
03:04
Colorimetric Detection of a Bacterial Biomarker Using a Modified Litmus Test
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2025
This video demonstrates a colorimetric E. coli detection method, involving an E. coli biomarker activating a DNAzyme, leading to cleavage of RNA linkage and detachment of a DNAzyme-urease conjugate. A subsequent colorimetric assay detects the E. coli biomarker through ammonia-induced pH changes.
04:12
Modified Yeast-One Hybrid Assay to Detect Heteromeric Protein Complex-DNA Interactions
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2025
In this video, we demonstrate the modified yeast one-hybrid assay, which detects multiple proteins interacting with target DNA. The transformed yeast cells contain the target DNA sequence upstream of the reporter gene. Additionally, they express transcription factor proteins. When the proteins form complexes and bind to the target DNA, the reporter gene is expressed and can be detected enzymatically.
12:45
Testing For Genetically Modified Foods
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2023
Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University Genetic modification of foods has been a controversial issue due to debated concerns over health and environmental safety. This experiment demonstrates technical understanding of how food DNA is genetically identified, allowing for educated decision making about the safety and potential dangers of using genetically modified organisms (GMOs) in food supplies. Polymerase Chain Reaction (PCR) is used to amplify food DNA...
FAQs
These approaches create a detectable difference between modified and unmodified cytosine before or during sequencing. Chemical conversion changes the behavior of selected bases, whereas enzymatic treatment uses modification-sensitive reactions to preserve or alter particular cytosine forms. Sequencing then records the resulting differences in pairing or readout, allowing researchers to infer where methylated or hydroxymethylated bases occur.
The two modified bases can produce different biological profiles, so treating them as one signal may obscure meaningful variation in genome regulation. Methods that distinguish them allow researchers to map methylation and hydroxymethylation separately. This separation supports more precise comparisons of gene-expression control, developmental states, tissues, and pathological samples.
A modification-sensitive treatment changes how a DNA base is converted, retained, or interpreted during sequencing. The resulting sequence pattern is compared with the expected pattern for unmodified DNA, and differences identify candidate modified cytosines. Mapping these signals across the genome produces profiles that can be related to regulation of genome function.
Chemical conversion, enzymatic treatment, and modification-sensitive sequencing rely on different ways to create contrast between cytosine forms. Chemical methods alter base behavior, enzymatic methods exploit selective reactions, and sequencing-focused approaches detect modification-dependent readout patterns. Their shared purpose is to resolve modified from unmodified cytosine, while the chosen mechanism determines how the resulting profile is generated.
A typical workflow begins with DNA from the biological sample, followed by a chemical conversion, enzymatic treatment, or other modification-sensitive step. The treated DNA is then analyzed by sequencing or a related readout, and the signals are mapped to identify modified cytosine positions. The resulting profile can be compared across samples, tissues, or developmental conditions.
Researchers apply this analysis when they need to compare epigenetic patterns between developmental states, cell types, tissues, or pathological samples. The profiles can reveal changes associated with gene-expression control, cell differentiation, genomic imprinting, or disease. Because the measurements identify molecular differences in cytosine modification, they also support comparisons that are not apparent from sequence information alone.
Comparing these profiles can show whether biological samples differ in the distribution of 5-methylcytosine, 5-hydroxymethylcytosine, or both. Such differences provide molecular markers for distinguishing developmental states, tissues, and disease-associated samples. In biology, the comparisons help connect cytosine modification patterns with epigenetic regulation and changes in genome function.