Part 1: Removing Plate 1 from the Chamber

The answer to the previous question was Plate 1H. A plate is ready to be taken out of the developing chamber when the solvent front has reached approximately 0.5 cm from the top of the plate. Removing a plate from the chamber too early or too late will result in poor separation of spots.

Once you've removed the plate from the chamber, it is important to draw a line across the solvent front immediately, before the plate dries. Once the plate dries, you will not be able to tell how far the solvent went up the plate. This makes it impossible to calculate accurate Rf values.