CEMS Continuous Emission

Have you from time to time been questioning the quantitative data you get from Bradford, Lowry or BCA protein quantification assays? These traditional methods are very fast and can be performed internally in most laboratories. They are based on dye-based UV spectroscopy by determining the concentration of the protein relative to a standard. Unfortunately, these assays are prone to interference from chemicals. They will not show if a recombinant protein sample has been contaminated by other proteins or by amino acids. The result is that all your experiments based upon these quantitative numbers are wrong. Just imagine the impact this will have on your enzymatic assay, your extinction coefficient or your upstream and downstream process development. Yes, this is definitely not a scenario you would want to experience. This is why you should use amino acid analysis (AAA) for your crucial protein quantification tasks.

There are several good reasons for why you should use AAA when you need quantitative data you can trust.

1. It is a very robust analysis. It can be performed in the presence of salt and detergents, as it is based on ion-exchange chromatography. The only contaminant that can obstruct the analysis is a chemical containing primary amines. And even then it might still be possible to do an accurate quantification if the calculations can be based on amino acids not affected by the contaminant.
2. You can compare the results with the sequence. This is a very important feature of the analysis. By comparing the quantitative data for each amino acid residue with the amino acid sequence of the protein you will get information about the purity of your sample. If the data does not fit within a few residues, your sample most likely is contaminated by other proteins.
3. It is linear over a broad concentration range. The analysis can measure from 100-10.000 pmol with high linearity. Therefore, it is suitable for samples with unknown concentration.
4. Your data can be qualified by using internal and external references.

To read more about our AAA service, please visit Alphalyse website on Amino Acid Analysis.