“…The trinitrophenyl derivative of amino groups can be quantitated spectrophotometrically with much greater accuracy than is possible with ninhydrin (Habeeb, 1966). TNBS also has been used as a reagent to modify the amino groups of xanthine oxidase (Greenlee and Handler, 1964), cytochrome c (Takemori et al, 1962), and myosin adenosine triphosphate (Kubo etal.,I960).2…”