Wheat germ calmodulin sequence is unique in that it contains cysteine (Cys²⁶) and only a single tyrosine (Tyr¹³⁸), in contrast to mammalian CaMs, which have two tyrosine residues and lack cysteine. This allows wheat germ CaM to be independently derivatized at both N- and C-terminal regions. Therefore it is ideal for applications requiring both calmodulin activation and residue specific tagging. Wheat germ CaM also has no tryptophan resulting in a distinctive absorbance spectrum when compared to mammalian CaM sequences. The conjugated formats are labelled at Cys²⁶.