Protein fragments separation is/are done by

GEL FILTRATION CHROMATOGAPHY It is also called molecuar sieving .Hyrophilic cross linked gels are used for seperation of molecules based on their size. The gel is packed in a column . The gel paicles are porous in nature . These pores will allw small molecules to enter into the gel. But larger molecules could not enter into the pores of the gel and so are excluded. The small molecules can enter the gel paicles ,then come out,re-enter into the another paicle.Small molecules are held back.But large molecules cannot enter the pores and sidetrack the gel paicles; so they move in the column rapidly.In sho ,larger molecules will come out first, while smaller molecules are retained in the column. REFERNCE : DM VASUDEVAN TEXTBOOK EIGHTH EDITION ; Page no :435