layer 5 mm thick after cooling and solidifying the plate was divided into four parts in a glass dish 200 ml of a solution of 15 budge and 10 1 n naoh in water was added to the parts and agitated for five hours at 50 rpm at ambient temperature the plates were soaked in running tap water for three hours then stored in water at 4 u00b0 c to detect the stabilization of agarose due to crosslinking approx 5 g was boiled for ten minutes with 5 ml water in a test tube during which the piece of agarose retained its shape i e the agarose did not go into solution the plates were divided into pieces approx 2 cm in size and were transferred to a glass bottle together with 200 ml water the pieces were treated for 30 minutes in an ultraturrax homogenizer model t25 from janke and kunkel at the highest setting approx 24 000 revolutions per minute with water cooling the resulting gel was placed in 80 ml falcon tubes and was centrifuged for five minutes at ambient temperature in a laboratory centrifuge the supernatant was decanted and an equal amount of water was added to the tubes the gel was resuspended and centrifuged at.