Spectrophotometry

Our facility houses one spectrophotometer, a Nanodrop ND-1000. Spectrophotometers are used to read the absorbance of liquid samples. Our Nanodrop requires only 1 or 2 µls of sample.


Spectrophotometry is often used to assess DNA or Protein concentration in a sample. The Nanodrop Spectrophotometer has software which will give the concentration of a DNA/RNA or Protein sample. It also has several other modes for specific protein assays or bacterial concentration. Below is an example of a DNA reading from the Nanodrop, as well as what each of the numbers mean.

DNA reading from the Nanodrop Spectrophotometer

Results from a DNA sample

Gives concentration of sample in ng/μl

260/230 ratio = Organic chemicals and solvent contamination

• Important to have this ratio above 1.6 for QPCR

260/280 ratio = Protein Contamination

• Ratios above 1.8 are considered pure

Additional Information: