Hi,

I think it depends on your experimental work, but in general water is best solvent for amino acids

Thanks

Sarkawt 

If you are using silica gel plates then try n-butanol:acetic acid:water 3:1:1 (by volume)  as per Reach Devices visit: http://www.reachdevices.com/TLC_aminoacids.html

For a recent review of TLC of amino acids see link.

http://www.reachdevices.com/TLC_aminoacids.html

Article Thin-layer chromatography of amino acids: A review

Increase the ratio of water