Using the GeneQuant II spectrophotometer

• Make 1 in 20 dilutions of samples (i.e. 5 uL DNA + 95 uL H₂O)
• Turn on the spec (switch at back) and press the set-up key
• The following settings are important:
  • Path length = 10
  • Use 320 nm = YES
  • Dilute = 20.00
  • Factor: dsDNA 50.0
• Set reference: take 100 uL of dd H₂O in the cuvette and press the set-ref key. You should get an ABS260 reading of 0.0000
• Remove the water from the cuvette using the vacuum manifold
• Put first sample in the cuvette and press the sample key
• Note down the ABS reading, the ratio and the concentration (you can choose the units using the select key)
• Remove sample using the vacuum, and rinse out the cuvette with dd H₂O (preferably twice)
• Repeat with next sample and so forth
• When finished, rinse out the cuvette with 0.1 M NaOH, followed by 0.1 M HCl, followed by dd H₂O a few times
• Remember to turn off the machine and put its cover back on!