For preparing the onion tissue extract:

Liquidizer

Sharp vegetable knife and chopping board

Water bath set at 60^oC

Ice, in a jug

Thermometer

250 cm³ beakers, 2

Coffee filter paper (do not use laboratory filter paper)

Onion, about 100 g

Washing-up liquid, 10 cm³ (do not use the thicker, concentrated type)

Sodium chloride, 3 g

Distilled water, 100 cm³
 
 

For separating the DNA from the onion extract:

Slender glass rod

10 cm³ syringe for measuring out liquids

Boiling tube Rack or small beaker for holding boiling tube

Onion extract (see below), 6 cm³

Protease enzyme, Novo Nordisk Neutrase, 4 drops

Ice cold 95% ethanol, 9 cm³
 
 
 

NOTE: it is important to use this concentration of ethanol. Place it in a freezer in a
               plastic bottle overnight to ensure that it is ice cold.