Sulforhodamine B assay and chemosensitivity

Area of Science:

• Biochemistry
• Cell Biology
• Pharmacology

Background:

• The sulforhodamine B (SRB) assay was developed for large-scale drug screening.
• It measures drug-induced cytotoxicity and cell proliferation.
• The assay relies on the electrostatic and pH-dependent binding of SRB dye to cellular proteins.

Purpose of the Study:

• To present the sulforhodamine B (SRB) assay for drug-induced cytotoxicity and cell proliferation.
• To highlight its suitability for large-scale drug-screening applications.

Main Methods:

• Cells are fixed with trichloroacetic acid.
• Sulforhodamine B dye binds to cellular proteins under mild acidic conditions.
• Dye is extracted and solubilized under mild basic conditions for measurement.

Main Results:

• Assay results show linearity with cell number and protein content across a wide density range (1-200% confluence).
• SRB assay sensitivity is comparable to fluorescence assays and superior to Lowry or Bradford assays.
• The assay offers a favorable signal-to-noise ratio and resolution of 1000-2000 cells/well.

Conclusions:

• The SRB assay is a sensitive, stable, and non-destructive method for assessing drug-induced cytotoxicity.
• Its practical advantages make it suitable for large-scale drug screening applications.
• It performs comparably to other established cytotoxicity assays like MTT and clonogenic assays.