Site Directed Mutagenesis (SDM) Rat

DNA-protein interactions are studied by using ChIP. The basic steps in this technique are crosslinking, sonication, immunoprecipitation, and analysis of the immunoprecipitated DNA. During ChIP, if chromatin is under-fragmented or fragments are too large which can lead to the increased background and lower resolution. Shorter cross-linking times (5-10 min) and/or lower formaldehyde concentrations (<1%) may improve shearing efficiency. If Chromatin is over-fragmented, then optimize shearing conditions for each cell type to improve ChIP efficiency. Over-sonication of chromatin may disrupt chromatin integrity and denature antibody epitopes. If you do not see any product or very little product in the input PCR reactions, add 5–10 μg chromatin per IP.

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.

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.

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.

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.