- UV spectrophotometer and cuvettes
- Alkaline-distilled water
- Dissolve 10 mg of commercial RNA in 250 mL of slightly alkaline distilled
water. Use a volumetric flask and proper analytical technique. This will
yield a standard solution of 40 micrograms RNA/mL.
- Prepare a series of dilutions so that you have 40, 20, 10, 5, and 2.5 micrograms
of RNA per mL.
- Turn on a UV spectrophotometer and adjust the wavelength to 260 nm.
Use the alkaline water to blank the spectrophotometer at 260 nm.
- Read the A260 of each of the standards. Plot the A260 versus the concentration
of RNA and calculate the extinction coefficient.
- Dissolve your isolated, precipitated RNA in 10.0 mL of alkaline water.
Prepare a serial dilution for 1/10, 1/100, 1/1000, and 1/10000. Measure
the absorbance of each at 260 nm and, using the dilution that produces
a reading between .1 and 1.5 absorbance units, compute the concentration
of RNA in your sample.