Apurinic/apyrimidinic (AP or abasic) sites are deoxyribonucleic acid (DNA) lesions that result from the loss of a nucleobase by hydrolysis of the "N"-glycosyl bond. AP sites are the most frequent lesions in cells and are caused by environmental and cancer therapeutic genotoxins. Herein, the bicinchoninic colorimetric assay, typically used to quantify proteins, is used to quantify abasic sites within DNA nucleotides. The abasic sites can be quantified using either a traditional colorimeter to measure absorbances at 562 nm or using hand-held cameras to measure the color change (e.g., green value). Having a rapid colorimetric method for quantifying abasic sites within DNA nucleotides would be beneficial within undergraduate teaching laboratories to introduce students to DNA structures and how DNA lesions are produced structurally.