Pre-labeled protein standards useful in electrophoresis that have sharp, consistent separation characteristics that are substantially the same as those of their unlabeled counterparts are provided. The invention provides pre-labeled protein standard sets that include a plurality of labeled proteins that are labeled on a first amino acid, in which side reactions of the label with amino acids not targeted for labeling are reduced.

Pre-labeled protein standards useful in electrophoresis that have sharp, consistent separation characteristics that are substantially the same as those of their unlabeled counterparts are provided. The invention provides pre-labeled protein standard sets that include a plurality of labeled proteins that are labeled on a first amino acid, in which side reactions of the label with amino acids not targeted for labeling are reduced.

The present invention relates to a cyclic peptide compound, and a preparation method, pharmaceutical composition and use thereof. In particular, the cyclic peptide compound of the present invention has a structure as shown by general formula (I). The compound of general formula (I), and isomers, racemates, pharmaceutically acceptable salts, crystalline hydrates, solvates or mixtures thereof have a use in the preparation of medicaments for preventing or treating mammalian diseases associated with histone deacetylase dysregulations. ##STR00001##

Pre-labeled protein standards useful in electrophoresis that have sharp, consistent separation characteristics that are substantially the same as those of their unlabeled counterparts are provided. The invention provides pre-labeled protein standard sets that include a plurality of labeled proteins that are labeled on a first amino acid, in which side reactions of the label with amino acids not targeted for labeling are reduced.