DNA isolation / purification Cells

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.

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.

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.

There are a plethora of detection methods of cell cytotoxicity and proliferation by flow cytometry. However, samples preparation for such flow cytometry-based techniques could be challenging. Cell harvesting by trypsinization, mechanical or enzymatic cell disaggregation from tissues, extensive centrifugation steps, may all lead to preferential loss of apoptotic cells. To overcome this strictly follow manufacturers instruction of the detection kit.

Gene silencing through the use of small interfering RNA (siRNA) has become a primary tool for identifying disease-causing genes. There are several aspects for preparing and delivering effective siRNA to knockdown a target gene. The length of siRNA should be 21–23nt long with G/C content 30–50%. If a validated siRNA sequence for your target gene is not available, use siRNA generated against the entire target gene ORF. Always work with two or three different siRNA constructs to get reliable results. If you are not sure how much siRNA to use for a given experiment, start with a transfection concentration of 10-50 nM and use siRNA-specific transfection reagent to ensure efficient siRNA delivery in a wide range of cells.

Gene silencing through the use of small interfering RNA (siRNA) has become a primary tool for identifying disease-causing genes. There are several aspects for preparing and delivering effective siRNA to knockdown a target gene. The length of siRNA should be 21–23nt long with G/C content 30–50%. If a validated siRNA sequence for your target gene is not available, use siRNA generated against the entire target gene ORF. Always work with two or three different siRNA constructs to get reliable results. If you are not sure how much siRNA to use for a given experiment, start with a transfection concentration of 10-50 nM and use siRNA-specific transfection reagent to ensure efficient siRNA delivery in a wide range of cells.

In ChIP, the most vital step is the binding of an antibody and choosing the right antibody. The binding affinity of different types of immunoglobulins to protein A or G differs significantly. Henceforth, it is recommended to choose either protein A or protein G coated beads. If you do not see any product in the positive control, add 5–10 μg of chromatin and 1–5 μg of antibody to each IP reaction and incubate with antibody overnight and an additional 2 hr after adding Protein G/A beads. If no product in the experimental, add more DNA to the PCR reaction or increase the number of amplification cycles. Choose an alternate, ChIP-validated antibody if the antibody does not work.

In ChIP, the most vital step is the binding of an antibody and choosing the right antibody. The binding affinity of different types of immunoglobulins to protein A or G differs significantly. Henceforth, it is recommended to choose either protein A or protein G coated beads. If you do not see any product in the positive control, add 5–10 μg of chromatin and 1–5 μg of antibody to each IP reaction and incubate with antibody overnight and an additional 2 hr after adding Protein G/A beads. If no product in the experimental, add more DNA to the PCR reaction or increase the number of amplification cycles. Choose an alternate, ChIP-validated antibody if the antibody does not work.

In ChIP, the most vital step is the binding of an antibody and choosing the right antibody. The binding affinity of different types of immunoglobulins to protein A or G differs significantly. Henceforth, it is recommended to choose either protein A or protein G coated beads. If you do not see any product in the positive control, add 5–10 μg of chromatin and 1–5 μg of antibody to each IP reaction and incubate with antibody overnight and an additional 2 hr after adding Protein G/A beads. If no product in the experimental, add more DNA to the PCR reaction or increase the number of amplification cycles. Choose an alternate, ChIP-validated antibody if the antibody does not work.

In ChIP, the most vital step is the binding of an antibody and choosing the right antibody. The binding affinity of different types of immunoglobulins to protein A or G differs significantly. Henceforth, it is recommended to choose either protein A or protein G coated beads. If you do not see any product in the positive control, add 5–10 μg of chromatin and 1–5 μg of antibody to each IP reaction and incubate with antibody overnight and an additional 2 hr after adding Protein G/A beads. If no product in the experimental, add more DNA to the PCR reaction or increase the number of amplification cycles. Choose an alternate, ChIP-validated antibody if the antibody does not work.