Second trial: To overcome this trouble, 1 spatula urea is added ( 3 – 4M) to 100 ul of the SDS-samples, see figure 3 . The effect of this procedure: Samples 1 – 5 stay in their slots.
Adding of urea in slot 5 was not sufficient. This sample migrates very slow out of the slot, shrinking to a slim line. See fig. 2