Researchers at the University of California, Berkeley, have used SELDI and mass spectrometry to identify proteins that could potentially serve as markers for a benzene-exposure test.
The study is significant because benzene has been linked to leukemia and bone marrow damage, and US regulatory agencies have said they would investigate the effects of benzene exposure, says Martyn Smith, the leader of the study.
“What we’re interested in is an effective test [for benzene exposure],” says Smith, whose paper appears in the Nov. 22 Proceedings of the National Academy of Sciences.
While white blood cell counts are currently used to test for benzene exposure, a protein-based test that could be used in the field would be easier, he says.
“With blood counts, you have to collect blood in a certain way, send it off to a lab, and use an expensive machine to determine the counts,” Smith says. “It’s not a fingerprick in the field, if you know what I mean. If you had a blood spot, and you could just look at proteins in the blood, or maybe a chip that you could use in the field, that would be considerably easier.”
To find proteins that changed with benzene exposure, Smith and his colleagues first used Ciphergen’s SELDI chips to examine the proteomes of 10 Chinese shoe factory workers who had been exposed to an overall mean benzene air level of greater than 30 parts per million, and 10 controls who worked in a clothing manufacturing plant in the same geographical area.
The researchers found three proteins that were consistently down-regulated in people who had been exposed to benzene. They then purified the proteins and attempted to identify them using tandem mass spectrometry. Two of the proteins were successfully identified as platelet factor 4 and connective tissue activating peptide III.
— Tien-Shun Lee
US Patent No. 6,969,452. Two-dimensional protein separations using chromatofocusing and multiplexed capillary gel electrophoresis. Inventors: Yan He, Ho-Ming Pang, Siquan Luo, Futian Han. Assignee: Combisep. Issued: November 29, 2005.
This patent covers a method for two-dimensional protein separation by chromatofocusing into a plurality of aliquots, and then loading each aliquot into a separate capillary tube; and separating each aliquot by multiplexed capillary electrophoresis to produce a two-dimensional array of separated proteins, according to the abstract.
US Patent No. 6,969,614. Methods for the isolation and analysis of cellular protein content. Inventors: Lance Liotta, Nicole Simone, Michael Emmert-Buck, Emmanuel Petricoin. Assignee: The United States of America as represented by the Department of Health and Human Services. Issued: November 29, 2005.
This invention describes devices and methods for performing protein analysis on laser capture microdissected cells. In addition to permitting direct comparison of qualitative and quantitative protein content of tumor cells and normal cells from the same tissue sample, the methods also allow for investigation of protein characteristics of tumor cells.