Preparing the TLC Plate
Obtain a TLC plate of an appropriate size (generally between 5 and 10 cm in length). They are commonly cut from larger sheets (20 x20 cm) using a sharp knife. Try not to touch the surface of the plate any more than necessary to avoid getting grease and oil on it. Draw a light pencil line about 1 cm from the bottom of the plate.
Make small marks along the line at approximately 1 cm intervals.
Use a toothpick or narrow glass capillary to apply small spots of the sample and/or standards to the plate. The 1 cm markings are used as a guide to keep the spots far enough apart. The spots should be kept as small in diameter as possible. If additional sample/standard needs to be added, the original spot should be allowed to dry before it is respotted.
Allow the plate to dry completely.