DNA extraction with gene clean


  • excise piece of agarose with the DNA fragment or use solution containing DNA
  • add NaI solution (3 x the weight/volume, 300 µl of NaI solution to 0,1 g or 100 µl)
  • incubate at 55°C to completely dissolve agarose (5 min), mix from time to time
  • put on ice, add 5µl of glass beads, suspend well
  • incubate for 5 to 10 min on ice, mix frequently
  • spin briefly, discard supernatant, add 500 µl wash solution, suspend well, be care with fragments longer than 5 kb
  • repeat wash twice
  • spin briefly, remove traces of wash solution
  • elute DNA by suspending glass beads in 7 µl water, incubate at 55°C for 3 min
  • spin, save supernatant, be careful not to transfer any glass beads
  • repeat elution step 

incubating the glass beads on ice for binding and at 55°C for elution increases the yield.
The glass beads should be at 50% (v/v). If more, dilute with water.
For large amount of DNA (more than 5 µg), use 1µl glass beads for each additional µg of DNA, using glass beads in surplus results in low yields.
Make sure that the pH of the NaI solution is less than 8 to allow efficient binding (if necessary add 10% acetic acid). Make sure that elution is not at low pH, you may use 10 mM Tris/HCl pH8 for elution instead of dd water.