Lowry protein assay
Overview
Biochemistry
Biochemistry, sometimes called biological chemistry, is the study of chemical processes in living organisms, including, but not limited to, living matter. Biochemistry governs all living organisms and living processes...
assay
Assay
An assay is a procedure in molecular biology for testing or measuring the activity of a drug or biochemical in an organism or organic sample. A quantitative assay may also measure the amount of a substance in a sample. Bioassays and immunoassays are among the many varieties of specialized...
for determining the total level of protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
in a solution. The total protein concentration is exhibited by a color change of the sample solution in proportion to protein concentration, which can then be measured using colorimetric
Colorimetry
Colorimetry is "the science and technology used to quantify and describe physically the human color perception."It is similar to spectrophotometry, but is distinguished by its interest in reducing spectra to the physical correlates of color perception, most often the CIE 1931 XYZ color space...
techniques. It is named for the biochemist Oliver H. Lowry
Oliver Lowry
Oliver Howe Lowry was an American biochemist. He is best remembered for devising the Lowry protein assay.Lowry was the youngest of a family of five children. His father was a teacher and later an administrator in the Chicago public school system...
who developed the technique in the 1940s. His 1951 paper describing the technique is one of the most-highly cited papers ever in the scientific literature, cited over 200,000 times.
The method combines the reactions of copper ions with the peptide bond
Peptide bond
This article is about the peptide link found within biological molecules, such as proteins. A similar article for synthetic molecules is being created...
s under alkaline conditions (the Biuret test
Biuret test
The biuret test is a chemical test used for detecting the presence of peptide bonds. In the presence of peptides, a copper ion forms a violet-colored complex in an alkaline solution...
) with the oxidation of aromatic protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
residues.
Unanswered Questions
