Home DNA extraction

How can you isolate DNA in your own kitchen?

Safe­ty pre­cau­tions

Con­duct this ex­per­i­ment only un­der adult su­per­vi­sion.

Reagents and equip­ment

  • ba­nana;
  • 200 mL iso­propyl al­co­hol;
  • 1 tbsp ta­ble salt;
  • 10 drops of liq­uid soap con­tain­ing sodi­um do­de­cyl sul­fate;
  • 100 mL hot wa­ter;
  • 100 mL cold wa­ter;
  • shot glass;
  • blender;
  • glass­es;
  • gauze;
  • colan­der;
  • deep dish.

Step-by-step in­struc­tions

Pre­pare a pre­cip­i­tat­ing so­lu­tion: com­bine 1 tbsp ta­ble salt and 10 drops of liq­uid soap con­tain­ing sodi­um do­de­cyl sul­fate in a glass. Add 100 mL hot wa­ter. Stir well.

Place a peeled ba­nana in a glass. Add 5 ta­ble­spoons of pre­cip­i­tat­ing so­lu­tion and 100 mL cold wa­ter. Blend the mix­ture thor­ough­ly.

Fil­ter the puree through sev­er­al lay­ers of gauze. Care­ful­ly add 200 mL ice-cold iso­propyl al­co­hol by pour­ing the liq­uid down the side of the glass. Ob­serve the for­ma­tion of a white mass in the al­co­hol lay­er.

Process de­scrip­tion

DNA is a mol­e­cule with a com­plex struc­ture that stores and pass­es the ge­net­ic in­for­ma­tion of ev­ery liv­ing or­gan­ism on Earth from gen­er­a­tion to gen­er­a­tion. This sim­ple method for DNA ex­trac­tion is based on the fol­low­ing prin­ci­ples: the liq­uid soap con­tains sur­fac­tants, which help de­stroy the cell mem­branes and nu­clei, while sodi­um ions from the salt bind to the phos­phate groups of the DNA mol­e­cules, help­ing iso­late the DNA from the so­lu­tion. Adding cold iso­propyl al­co­hol re­duces the re­sult­ing DNA and sodi­um com­pound sol­u­bil­i­ty in wa­ter. You can also use this method to iso­late the DNA of straw­ber­ries, peach­es, and toma­toes.

Try it