Immunohistochemistry Desmin Goatt Mouse

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.

Short hairpin or small hairpin RNA (shRNA) is artificial RNA, which has a hairpin loop structure, and uses inherent microRNA (miRNA) machinery to silence target gene expression. This is called RNA interference (RNAi). These can be delivered via plasmids or viral/bacterial vectors. Challenges in shRNA-mediated gene silencing include 1. Off-target silencing, 2. Packaging shRNA encoding lentivirus, and 3. Stable transduction in cells. RNAi has been designed to have anywhere from 19-27 bs, but the most effective design has 19 bp. In case commercial shRNAs are not available, potential target sites can be chosen within exon, 5’- or 3’ UTR, depending on which splice variants of the gene are desired. One should use the latest algorithms and choose at least two different sequences, targeting different regions, in order to have confidence in overcoming off-target effects. A BLAST search after selecting potential design will eliminate potential off-target sequences. For the second challenge, sequencing the vector using primers for either strand (50-100 bp upstream) is suggested, along with using enzymatic digestion on agarose gel for the vector. Next, once the shRNA-containing vector is packaged in a virus, it is important to check the viral titer before transduction. Finally, using a marker in the lentiviral vector (fluorescent protein or antibiotic resistance), along with qPCR for target gene expression can help in determining the efficacy of transduction and shRNA on its target site.

miRNA is the inherent gene silencing machinery which can have more than one mRNA target, whereas siRNA can be designed to target a particular mRNA target. By design, both siRNA and miRNA are 20-25 nucleotides in length. The target sequence for siRNAs is usually located within the open reading frame, between 50 and 100 nucleotides downstream of the start codon. There are two ways in which cells can be transfected with desired RNAi: 1. Direct transfection (with calcium phosphate co-precipitation or cationic lipid mediated transfection using lipofectamine or oligofectamine), and 2. Making RNAi lentiviral constructs (followed by transformation and transduction). Lentiviral constructs are time consuming, but provide a more permanent expression of RNAi in the cells, and consistent gene silencing. Direct transfection of oligonucleotides provides temporary genetic suppression. Traditional methods like calcium phosphate co-precipitation have challenges like low efficiency, poor reproducibility and cell toxicity. Whereas, cationic lipid-based transfection reagents are able to overcome these challenges, along with applicability to a large variety of eukaryotic cell lines. When using oligos, the ideal concentration lies between 10-50nM for effective transfection.

miRNA is the inherent gene silencing machinery which can have more than one mRNA target, whereas siRNA can be designed to target a particular mRNA target. By design, both siRNA and miRNA are 20-25 nucleotides in length. The target sequence for siRNAs is usually located within the open reading frame, between 50 and 100 nucleotides downstream of the start codon. There are two ways in which cells can be transfected with desired RNAi: 1. Direct transfection (with calcium phosphate co-precipitation or cationic lipid mediated transfection using lipofectamine or oligofectamine), and 2. Making RNAi lentiviral constructs (followed by transformation and transduction). Lentiviral constructs are time consuming, but provide a more permanent expression of RNAi in the cells, and consistent gene silencing. Direct transfection of oligonucleotides provides temporary genetic suppression. Traditional methods like calcium phosphate co-precipitation have challenges like low efficiency, poor reproducibility and cell toxicity. Whereas, cationic lipid-based transfection reagents are able to overcome these challenges, along with applicability to a large variety of eukaryotic cell lines. When using oligos, the ideal concentration lies between 10-50nM for effective transfection.

Get tips on using Purified anti-mouse CD274 (B7-H1, PD-L1) Antibody to perform Flow cytometry Anti-bodies Mouse - CD274/PD-L1

Get tips on using APC anti-mouse CD274 (B7-H1, PD-L1) Antibody to perform Flow cytometry Anti-bodies Mouse - CD274/PD-L1

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Get tips on using Monoclonal Anti-ACTA2 antibody produced in mouse to perform Western blotting Smooth muscle actin

Though DNA quantification is but one small step in the multifaceted DNA sample preparation workflow, it can have large implications on the performance and validity of conclusions drawn from downstream assays. Major challenges include accuracy, precision, reproducibility, and detection of present contamination. Among UV spectrophotometry, fluorescence and real-time PCR based methods, the quantification method should be chosen based on the requirement of the downstream assay .

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.