Quantitative single cell and single molecule proteomics for clinical studies.

A central aspect of cellular systems biology is the study of cell-to-cell variability driven by network control of molecular noise. Proteins are produced in stochastic bursts and, although time averaging smoothes their accumulated levels, variation in their copy number is substantial in members of environmental sensing and signalling networks. We have developed a label-free, microfluidic antibody capture chip platform called the MAC chip, to quantify precisely the copy numbers of many proteins from a single cell in a multiplexed single assay format. We intend to investigate protein noise in circulating tumour cells (CTCs) isolated from biopsies of cancer patients through the identification of biomolecular signatures, such as p53 tumour suppressor protein, which correlate with biological properties and clinical outcomes during treatment.