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Updated: May 29, 2026

Microvolume Protein Concentration Determination using the NanoDrop 2000c Spectrophotometer
Published on: November 4, 2009
Assays for determination of protein concentration
Bradley J S C Olson1, John Markwell
1Michigan State University, East Lansing, MI, USA.
Abstract:
Biochemical analysis of proteins relies on accurate quantitation of protein concentration. This appendix describes how to perform commonly used protein assays, e.g., Lowry, Bradford, BCA, and UV spectroscopic protein assays. The primary focus of the appendix is assay selection, emphasizing sample and buffer compatibility. Protein assay standard curves and data processing fundamentals are discussed in detail. This appendix also details high-throughput adaptations of the commonly used protein assays, and also contains a protocol for BCA assay of total protein in SDS-PAGE sample buffer that is used for equal loading of SDS-PAGE gels, which is reliable, inexpensive, and quick.
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