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- Turn on machine and wait for it to warm up
- Wash glass cuvettes thoroughly before use and if 2 are used then make sure they are a matching pair.
- For Spec. in Dave Andersons bay then press goto ? type in 260 press enter machine will change wavelength. Insert 1ml of water into machine and press autozero For other machines then set wavelength to 260 and autozero with water.
- Put 5m l of DNA concentration? into a clean matching cuvette, add 1ml of water and mix by covering with parafilm and inverting.
- Insert cuvette into machine and note reading i.e. 0.030.
- Follow steps 3 again but this time set wavelength to 280, note reading.
- Repeat procedure 3 times with new samples of DNA noting readings at both A260 and A280.
- Take an average of the A260 readings and multiply the figure by 10 to give the concentration of DNA per ml. i.e. 0.030 x 10 = 3.0mg/ml
- Take average of A280 readings and divide A260 average by the A280 average this should give a figure between 1.8-2.0 if it is out of the range then the DNA is not pure and sample should be purified using phenol/chloroform.