Sobia: As lectins bind specific carbohydrates (oligosaccharides) depending on their production by different plants.  You need first to know the major lectin(s) produced by your starting material (seeds), and then look for the specific oligosaccharide conjugated to matrix as a purification column (e.g., mannan-agarose for Con A).  If you don't know that, then you need to use a variaty of oligosaccharides to screen for the specificities.  It's a long way to reach to a purified lectin from an unknown source.  Good luck.

Thank you.

For lectins that cannot tolerate organic solvents we proceed with aqueous extraction, followed by ammonium sulfate precipitation, Hydrophobic Interaction Chromatography (Phenyl medium to high-substitution), Anion-Exchange (CaptoQ, EnrichQ, etc), and SEC using bioactivity guided fraction to identify the fractions containing lectin. (Isolation and identification of Griffithsin: http://www.jbc.org/content/280/10/9345.long). 

For lectins that can tolerate organic solvents we take the extract, load onto a C4 SPE vacuum cartridge and elute with increasing concentration of MeOH (10% step increases), dry under vacuum, then load onto a size exclusion G-100, the active fraction from G-100 concentrated with spin filtration, and loaded onto RPLC - C18 eluted with increasing acetonitril. (Isolation and identification of Scytovirin: http://pubs.acs.org/doi/pdf/10.1021/bi0205698).

Good luck! There are loads of lectins isolated from plants in the literature that should help guide you to the appropriate purification scheme. Specifically, you might want to look at the monocot consensus fold lectins (NPL, GNA, SCL, HHA, etc) if that applies to your samples.

THANK YOU SO MUCH