Journal of Chemical Ecology

, Volume 15, Issue 3, pp 979–992

Measuring plant protein with the Bradford assay

1. Evaluation and standard method
  • Clive G. Jones
  • J. Daniel Hare
  • Steve J. Compton

DOI: 10.1007/BF01015193

Cite this article as:
Jones, C.G., Daniel Hare, J. & Compton, S.J. J Chem Ecol (1989) 15: 979. doi:10.1007/BF01015193


The suitability of the Bradford protein assay for measuring plant protein was evaluated and a standard method developed. The assay involves extraction of dried, fresh, or frozen plant material in 0.1 NaOH for 30 min. Replicate 100-μl aliquots of centrifuged supernatant are assayed with 5 ml Bio-Rad Bradford dye reagent (Coomassie brilliant blue G-250) diluted 1:4 and containing 3 mg/ml soluble polyvinylpyrollidone. Absorbance at 595 nm is recorded after 15 min against an NaOH blank. Samples are calibrated against a ribulose 1,5-diphosphate carboxylase-oxygenase standard in NaOH. Procedures for plant preparation, extraction stability, the effects of phenol removal and quinone formation, and assay recovery are evaluated. Assay absorbance stability and techniques for increasing absorbance stability are reported. Changes in protein quality are briefly discussed.

Key words

Soluble protein Coomassie brilliant blue G-250 binding leaves extraction spectrophotometry protein assay 

Copyright information

© Plenum Publishing Corporation 1989

Authors and Affiliations

  • Clive G. Jones
    • 1
  • J. Daniel Hare
    • 2
  • Steve J. Compton
    • 1
  1. 1.Institute of Ecosystem StudiesThe New York Botanical GardenMillbrook
  2. 2.Department of EntomologyUniversity of CaliforniaRiverside
  3. 3.WAMI Program, Health Sciences CenterUniversity of Washington School of MedicineSeattle