Bio-Rad Quick Start™ Bradford Protein Assay - Manual (Page 27)

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5 May I use a wavelength other
than 595 nm?
6 Precipitation occurs in the
tubes.
7 Absorbance of protein standard
and samples is very low.
8 Absorbance of standard is
acceptable, but absorbance of
samples is very low.
Yes. Absorbance can be measured at
580–610 nm.
The samples contain a detergent in
the buffer. Dilute the sample to reduce
the detergent level or dialyze the
samples.
The 1x dye reagent may be cold from
4°C storage. Warm the dye reagent to
ambient temperature. The 1x dye
reagent may be old. If it is over 1 year
old, replace the dye reagent.
The samples may contain a sub-
stance that interferes with the
reaction, such as detergent or basic
solutions. Check the compatibility
guide (Table 1). Dilute the sample.
Ensure the standards are diluted in
the same buffer as the samples.
The molecular weight of the sample
protein may be low. The lower limit of
detection for this method is approxi-
mately 3,000–5,000 daltons.
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