In US: For Research Use Only. Not for Use in Diagnostic Procedures. ZYMUTEST™ Total Protein S (II) kit is an ELISA method for the in vitro quantitative determination of Total Protein S in human plasma. The ZYMUTEST™ Total Protein S (II) assay is specific for both forms of Protein S (free or complexed with C4b-BP) and is designed with a rabbit polyclonal antibody. First, the immunoconjugate, a rabbit polyclonal antibody specific for both forms of Protein S (free or complexed with C4b-Binding Protein) coupled to horse radish peroxidase(HRP), is introduced into the microwells coated with the same rabbit polyclonal antibody.