Protein: biomarker assays

Protein Biomarker Assays. NextGen Sciences has developed a mass spectrometry method for protein biomarker assays that does not depend on antibodies but instead uses surrogate proteins to facihtate development of assays. The mass spectrometer measures the amount of surrogate peptides and apphes statistical evaluation to assess each biomarker. This first stage requires that a protein be confirmed then only these selected proteins are used for the second stage of validation of these protein biomarkers. The mass spectrometry data are used along with carbon-13 or... 

Lee, J.W., Figeys, D., and Vasilescu, J. (2007) Biomarker assay translation from discovery to clinical studies in cancer drug development quantification of emerging protein biomarkers. In Sikora, K. (ed.), Genomics in Cancer Drug Discovery and Development. Advances in Cancer Research Hampton GM, Elsevier, pp. 269 298. 

As for immunoassays for pharmaceutical proteins, in-study validation of biomarker assays should include one set of calibrators to monitor the standard curve as well as a set of QC samples at three concentrations analyzed in duplicate for the decision to accept or reject a specific run. Recommended acceptance criterion is the 6-4-30 rule, but even more lenient acceptance criteria may be justified based on statistical rationale developed from experimental data [14]. 

Silicon nanowires incorporated into arrays provide label-free, multiplexed electrical detection of cancer protein biomarkers such as prostate-specific antigen at femtomolar concentrations with high sensitivity in clinically relevant serum samples [7]. Real-time assays of the binding, activity, and small-molecule inhibition of telomerase could be performed with this technique using unamplified extracts from as few as 10 tumor cells. This opens up substantial possibilities for diagnosis and treatment of cancer. 

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