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Updated: Mar 15, 2026

Highly Sensitive and Quantitative Detection of Proteins and Their Isoforms by Capillary Isoelectric Focusing Method
Published on: September 19, 2018
Detection of Isoforms Differing by a Single Charge Unit in Individual Cells
Augusto M Tentori1,2, Kevin A Yamauchi1, Amy E Herr3,4
1The UC Berkeley/UCSF Graduate Program in Bioengineering, Berkeley, CA, USA.
Abstract:
To measure protein isoforms in individual mammalian cells, we report single-cell resolution isoelectric focusing (scIEF) and high-selectivity immunoprobing. Microfluidic design and photoactivatable materials establish the tunable pH gradients required by IEF and precisely control the transport and handling of each 17-pL cell lysate during analysis. The scIEF assay resolves protein isoforms with resolution down to a single-charge unit, including both endogenous cytoplasmic and nuclear proteins from individual mammalian cells.
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