Edman's reagent is

Ans. is 'c' i.e., Phenyl-isocyanateDetermination of amino acid sequence (sequence analysis) is performed by Edman degradation method on automatic mechines, called cyclic sequentors. Edman's reagent is phenyl-isothiocyanate, and forms a covalent bond to N-terminal of amino-acid. This can be identified.Sanger's reagent (1-fluoro-2,4-dinitrobenzene) can be used in place of Edman's reagent.