Although most of these cleavable cross-linkers are commercially available and have a tremendous analytical value in the context of studies of protein-protein interactions, they are not affordable for producing a veterinary conjugate vaccines, characterized by their low prices . In addition, most of these cleavable cross-linkers have been designed to react with two primary amino groups separated by certain distance constrains, in the context of a 3D structure of multi-protein complexes, and they react randomly in a noncontrolled manner and in single step. This uncontrolled reactions conditions could disrupt the linear and conformational epitopes in the antigen which could be deleterious for the biological activity of a conjugate vaccine. In addition, to our knowledge there are not previous toxicology records and clinical experiences using the above-mentioned MS cleavable cross-linkers in conjugate vaccines or ADC.