dna-quantification-human-hela

The estimation of DNA methylation level heavily depends on the complete conversion of non-methylated DNA cytosines. It is crucial to ensure complete conversion of non-methylated cytosines in DNA. Therefore, it is important to incorporate controls for bisulfite reactions, as well as to pay attention to the appearance of cytosines in non-CpG sites after sequencing, which is an indicator of incomplete conversion.

The estimation of DNA methylation level heavily depends on the complete conversion of non-methylated DNA cytosines. It is crucial to ensure complete conversion of non-methylated cytosines in DNA. Therefore, it is important to incorporate controls for bisulfite reactions, as well as to pay attention to the appearance of cytosines in non-CpG sites after sequencing, which is an indicator of incomplete conversion.

The estimation of DNA methylation level heavily depends on the complete conversion of non-methylated DNA cytosines. It is crucial to ensure complete conversion of non-methylated cytosines in DNA. Therefore, it is important to incorporate controls for bisulfite reactions, as well as to pay attention to the appearance of cytosines in non-CpG sites after sequencing, which is an indicator of incomplete conversion.

Get tips on using MethylFlash Methylated DNA 5-mC Quantification Kit to perform DNA methylation profiling Whole genome profiling - C2C12 mouse myoblast cells

Isolating DNA from tissues and paraffin-embedded tissue samples can be challenging as double-stranded DNA is physically fragile and highly susceptible to exo- and endonucleases. The best solution is to slice the tissues into smaller pieces and make a homogenate solution (using tissue homogenizer or grinding liquid nitrogen frozen samples) in the presence of DNAse inhibitors. Further, extracting DNA from the nucleus need specific methods by combining physical, mechanical and chemical lysis approaches,

DNA microarrays enable researchers to monitor the expression of thousands of genes simultaneously. However, the sensitivity, accuracy, specificity, and reproducibility are major challenges for this technology. Cross-hybridization, combination with splice variants, is a prime source for the discrepancies in differential gene expression calls among various microarray platforms. Removing (either from production or downstream bioinformatic analysis) and/or redesigning the microarray probes prone to cross-hybridization is a reasonable strategy to increase the hybridization specificity and hence, the accuracy of the microarray measurements.

Transfection is a powerful technique that enables the study of the function of genes and gene products in cells. Based on the nature of experiments, we may need a stable DNA transfection in cells for persistent gain-of-function or loss-of-function of the target gene. For stable transfection, integration of a DNA vector into the chromosome is crucial which requires selective screening and clonal isolation. By carefully selecting a viral delivery system and related reagents we can ensure safe and highly-efficient delivery of expression constructs for high-level constitutive or inducible expression in any mammalian cell type.

RNA-Seq is a method to sequence RNA by applying Next Generation Sequencing (NGS). The quality of RNA is critical for the success of RNA-Seq. The integrity of RNA is measured by the RNA integrity number (RIN). RIN is computed from RNA electrophoresis and electropherogram profiles (the peak area of the 28S rRNA should be approximately twice the peak area of the 18S rRNA). If you get the RIN value lower than 7, the possibility of getting the low quality of RNA-seq data is high. To get a high quality RNA, it is better to work with fresh samples or snap-freeze the tissues in liquid nitrogen as quickly as possible and store them at -80°C until further use. Make sure designated areas and all your filter tips, microfuge tubes, plastic, and glassware are RNase-free.

Cell cycle can be challenging due to difference introduced by sample handling, timing, and difference within the sample. Downstream instriuments to analyse cell cycle (Multicolor flow cytometry and multicolor imaging) can answer these challenges. Relevant markers can be combined with cell phenotyping markers to look at events within subpopulations of cells.

TUNEL assay is the cell death detection method where the biochemical marker of apoptosis is DNA fragmentation. The assay involves the microscopical detection of generated DNA fragments with free 3'-hydroxyl residues. in apoptotic cells using enzyme terminal deoxynucleotidyl transferase (TdT) which adds biotinylated nucleotides at the site of DNA breaks. Major challenges of this method involve proper access of the enzyme which could be hampered by poor permeabilization and/or excessive fixation with cross-linking fixative (common with archival tissue). This issue can be resolved by optimizing the incubation time with Proteinase K or CytoninTM.