Western blotting: evolution of an old analytical method to a new quantitative tool for biomarker measurements.

Western blotting (WB) is a widely used laboratory technique for detecting specific proteins in biological matrices. Recent advances in antibody production, automation, gel and membrane manufacturing and highly sensitive detection platforms have transformed WB from a labor-intensive and qualitative method into a highly reproducible and quantitative assay suitable for biomarker detection. Despite these significant improvements in the capabilities and efficiency of WB, there remain challenges that hinder its widespread application as a research, diagnostic (in two-tiered assays like Lyme disease testing) and drug development tool. This article describes recent innovations introduced to WB methodology and the remaining challenges that prevent its wider adoption for biomarker measurements throughout the drug development process.