The CAMAG Automatic TLC Sampler 4 (ATS 4) features fully automatic sample application for qualitative, quantitative and preparative planar chromatography. For screening and mass analyses the new software option "FreeMode" now allows application of up to 66 samples from the standard rack, or up to 96 samples from well plates onto two opposite edges of 3 HPTLC plates of 20 x 10 cm or 6 plates of 10 x 10 cm. Furthermore the TLC Sampler 4 is an excellent tool for development and manufacturing of test kits for diagnostic purposes because it can be used to apply antigen-/antibody solutions onto membranes (such as nitrocellulose). All relevant application patterns (for instance rows of spots or lines, parallel or on top of each other, as well as crosses) can be created.