Determine the concentration of RNA with an absorbance readin

Solution

An A₂₆₀ reading of 1.0 is equivalent to ~40 µg/ml single-stranded RNA.

Concentration of RNA = A₂₆₀ reading X dilution factor X 40

                                        = 0.340 X 20 X 40

                                        = 272 µg.ml

Concentration of RNA = A₂₈₀ reading X dilution X 40

                                        = 0.150 X 20 X 40

                                        = 120 µg/ml

So, the ratio is – concentration of RNA at A260/concentration of RNA at A280 =272/120= 2.3 ~ 2