Figure 3.

Sensor characterization using a protein standard. (A) Serial dilutions of recombinant β-catenin standard were used to assess sensor performance across 5 orders of magnitude in 10 mM PBST/B buffer. The net shift from the enzymatic signal enhancement step with the net shift from off target mouse IgG isotype control was used as readout. The sensor has a linear dynamic range of 3.55-log with a limit of detection (LOD) of 0.6 pM (solid horizontal black line) and limit of quantification (LOQ) of 1.3 pM (dashed horizontal black line). The data was fit to a logistic function (red trace, adjusted r-squared >0.99). Error bars, SD (n = 3). (B) The minimum sample input for detection of β-catenin cell lysate was determined. The minimum input is between 1000 and 10,000 cells, whereas typical yield of most biopsy methods is >100,000 cells, including fine needle aspirates. The data was fit to a logistic function with adjusted r-squared of 0.985. Error bars represent ± SD (n = 3).