• Quantification of Total Human Alpha-1 Antitrypsin by Sandwich ELISA

      Tang, Qiushi; Gruntman, Alisha; Flotte, Terence R. (2017-07-28)
      In this chapter we describe an enzyme-linked immunosorbent assay (ELISA) to quantitatively measure human alpha-1 antitrypsin (AAT) protein levels in serum, other body fluids or liquid media. This assay can be used to measure the expression of the human AAT (hAAT) gene in a variety of gene transfer or gene downregulation experiments.A hAAT-specific capture antibody and a HRP-conjugated anti-AAT detection antibody are used in this assay. The conjugated anti-AAT used in this protocol, instead of the typical sandwich which employs an unconjugated antibody followed by a specifically conjugated IgG, makes the assay simpler and decreases variability. This provides a useful tool to evaluate the AAT levels in clinical and research samples and can allow fairly rapid testing of a large number of samples.
    • Quantification of Z-AAT by a Z-Specific "Sandwich" ELISA

      Borel, Florie; Tang, Qiushi; Mueller, Christian (2017-07-28)
      This protocol describes an enzyme-linked immunosorbent assay (ELISA) to specifically detect Z-alpha-1 antitrypsin (AAT), the most common protein variant associated with alpha-1 antitrypsin deficiency. This "sandwich" ELISA relies on an anti-Z-AAT specific capture antibody and a HRP-conjugated anti-AAT detection antibody. This method would be of interest to identify and quantify Z-AAT in a variety of samples such as cell culture medium, cell or tissue lysate, animal or patient serum. Because this method is specific and sensitive, it would be particularly valuable for detection of Z-AAT in the presence of background M-AAT, for instance when quantifying silencing of Z-AAT in patients undergoing M-AAT augmentation therapy.