Protein expression and purification Mammalian cells HeLa

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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.

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.

A PCR reaction consists of the template DNA, two primers covering the amplification site, an enzyme, and buffers. However, non-specific product amplification and primer-dimer formation during set-up are major causes of PCR failure. Nevertheless, high-quality DNA polymerase and optimize reaction buffers will certainly lead to a successful PCR reaction

A PCR reaction consists of the template DNA, two primers covering the amplification site, an enzyme, and buffers. However, non-specific product amplification and primer-dimer formation during set-up are major causes of PCR failure. Nevertheless, high-quality DNA polymerase and optimize reaction buffers will certainly lead to a successful PCR reaction.

A PCR reaction consists of the template DNA, two primers covering the amplification site, an enzyme, and buffers. Multiplexing such a reaction amplifies the design challenges where one target requires 3 primers, which should be exclusively bound nowhere in the template DNA or to each other. Similarly, two targets require 6, three require 9, and so on. Each amplicon needs to be either a different size (for gels) or labeled with a different fluorescent tag that is spectrally distinct from the others in the reaction. Further complicating this, different targets in the reaction can compete with each other for resources and causes more challenges in the detection of amplicons. However, with proper primer designing, their validation, optimize quality and concentration of the enzyme and buffers certainly lead to a successful multiplex PCR reaction.

Get tips on using pYT379-CDK8-CycC-10xHis complex to perform Protein Expression Eukaryotic cells - S. frugiperda CDK8-CycC-10xHis complex

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The most widely used method for protein quantification is by spectrophotometry. The concentration of the protein in the samples is measured at an absorbance of 280 nm. The absorbance of the sample protein is then plotted against a standard curve. This method allows for total protein quantification in a sample (cell and tissue extracts). Before analysing the concentration of protein in the sample, it is important to choose the right test method.  For high protein concentration samples (above 5 - 160 mg/ml) the best method is to use the Biuret test. For low concentrations samples (between 1 - 2000µg/ml) the best methods are Lowry assay, BCA assay, Bradford assay and coomassie blue (for exact sensitivity of the test kits you use, refer to manufacturer's protocol). If the samples contain detergents like Triton X-100 then BCA assay is the best choice. For samples that have proteins larger than 3 KDa in size Bradford assay is the best choice. Each method has advantages and disadvantages, plan your analysis considering your sample characteristics.