In the contact
bioautography, the TLC plate or paper chromatograms are placed
on the inoculated agar surface for some minutes or hours to allow
diffusion. Next, the plate is removed and the agar layer is incubated. The zones of inhibition growth appear in the places, where
the antimicrobial compounds were in contact with the agar layer.
In the immersion (agar-overlay) bioautography, the plate is first
immersed in or cover with agar medium, which after solidification is seeded with the tested microorganisms and then incubated