With years of experience and high-end technologies, Creative Biolabs has successfully developed a series of innovative and diversified assay platforms to provide fast and convenient services for our customers. We offer high-quality genetic/epigenetic analysis services for customers all over the world.
Epigenetics refers to the reversible regulation of gene expression, independent of the occurrence of DNA sequences. Epigenetic modifications, mediated by DNA methylation, histone tail modifications, and non-coding RNA interventions, make the genome susceptible to malignant progression. Chromatin remodeling by epigenetic reprogramming controls the regulation of gene expression and has important implications in the development of human cancers. Epigenetic mechanisms allow cells to alter their transcriptional activity, thereby permitting changes in gene expression without altering DNA sequence. There is also an increasing evidence for epigenetic modulation in response to environmental factors, and its implication in several human diseases such as cancer, neurodegenerative diseases, and cardiovascular diseases has been well established. Epigenetics can be triggered by any environmental signal, including UV, atmospheric pressure, food supply, plant nutrition, water supply, oxygen, chemicals, temperature and climate change.
Massively parallel sequencing technology lays the foundation for the construction of epigenomics. Creative Biolabs provides key sequencing-based methods used in the analysis of epigenomes.
5-methyl-cytosine (5mC) and its oxidized derivatives are measured on a genome-wide basis using enrichment and transformation methods followed by massively parallel sequencing. Bisulfite conversion provides a quantitative measurement of 5mC but does not distinguish 5hmC. Antibody enrichment provides qualitative measurements of 5mC and 5hmC. The bisulfite converted or enriched DNA is purified, library constructed and clonally sequenced. A special algorithm is needed to align the bisulfite conversion readings with the reference genome.
The genomic location of the modified histones is measured genome-wide by chromatin immunoprecipitation followed by massively parallel sequencing (ChIP-seq). Histones can be released from the genome by ultrasound, enzymatically digested, or inserted through a transposon. If sonication is used, chromatin must first be chemically cross-linked. After histone release, specific chemical modifications are enriched by immunoabsorption. Purification of enriched histone-associated DNA, which can be purified for high-throughput sequencing, provides complete information on specific DNA-protein interactions and binding sites.
The genomic location of long-range chromatin exposure is measured genome-wide by large-scale parallel sequencing of DNA fragments generated by adjacent ligation. Complete chromatin cross-linking physically connects adjacent genomic distal nucleosomes in 3-dimensional space. The cross-linked chromatin is enzymatically digested, and the resulting DNA ends are labeled with biotin and ligated adjacently. The ligated DNA is sheared by sonication or enzymatic digestion and the linked ligation is enriched by streptavidin pull-down. The resulting DNA is purified, library constructed and clonally sequenced. Chromosome conformation capture (3C) techniques provide the location of DNA fragments that interact based on their proximity to three-dimensional (3D) space. To measure whole-genome chromatin interactions, a single experiment typically requires 500 million sequences read.
Large-scale parallel sequencing of DNA fragments released from intact chromatin by transposon insertion, enzymatic digestion or sonication can measure the location of open chromatin in the genome-wide range. The obtained DNA fragment is subjected to size selection or phenol-chloroform extraction to eliminate nucleosome-associated DNA. The resulting DNA is purified, library constructed and sequenced, and aligned to the reference genome. Sequencing requirements depend on experimental parameters and resolution requirements, and range from 10 s to 100 s millions of fragments per sample.
With the help of our well-established technology and experienced scientists, in addition to providing quality technical services, we offer a very flexible choice for each specific epigenetic project design and implementation. Please don't hesitate to contact us for more information.
Reference
For Research Use Only. Not For Clinical Use.
