Bradford Lab Assay Report: Accurate Protein Concentration Measurement Using Spectroscopy

Running head: LAB ASSAY REPORT
PTS 9 BIC 3 The Bradford Lab Assay Report
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1LAB ASSAY REPORT
Abstract:
The development of Bradford Assay is attributed to Marion M.Bradford in 1970. The Assay
provides accurate and safe way of determining the concentration of proteins in the aqueous
solutions with help of Spectroscopy. The Coomassie dye is used to find out the presence of
proteins. The experiment used a standard curve with the data value ranges from 0 to 1.0 mg/ml
and implemented Bradford Assay to the data values. The concentration of protein as determined
in the sample A came to be 0.77 while in the second sample, the value came as 0.37 mg/ml.

2LAB ASSAY REPORT
Table of Contents
Introduction:....................................................................................................................................3
Materials and Methods:...................................................................................................................4
Results:............................................................................................................................................5
Discussion:.......................................................................................................................................7
References:......................................................................................................................................8

3LAB ASSAY REPORT
Introduction:
Marion M. Bradford developed Bradford Assay as the most accurate method of finding out the
protein in the aqueous solutions in 1970s (Bradford, 1976). It is considered safe; it is a rapidly
used and mostly accurate assay protocol for the assessing the protein concentration in aqueous
solution with help of spectroscopic analysis (Olson, 2016). It involves an estimation assay based
on colorimetry; the assay is solely dependent on the change of color of the solution to determine
the protein quantification. The change in intensity of color is determined by measuring the shift
in absorbance which is known as absorbance shift. The brilliant blue Coomasie Dye uses ionic
interactions to bind with the proteins. The dye exhibits red, green and blue color in the cationic,
neutral and anionic form respectively (Bio Rad, 2019) This assay uses the acidic state of
coomassie dye; the color change occurs from red to blue only after the dye binds to the desired
protein in solution (Grintzalis, Georgiou & Schneider, 2015). The interaction taking place
between dye and the protein of interest depends on the specific composition of amino acid
proteins being assayed. Coomassie has a binding affinity for aromatic amino acids. Absence of
protein in solution causes the color of coomassie to remain brownish throughout.
Bradford assay highlights several advantages over the other protein estimation assays such as
Folin and Biuret. This quick estimation assay is done within 30 minutes duration (Wiśniewski &
Gaugaz, 2015). The constant value of dye- albumin complex’s extinction coefficient remains
upto ten times its initial concentration being used in the assay. So, Beer’s Law can provide high
accuracy to the results while helping in maintaining an appropriate ratio of dye and the sample
analyte.