Figure 1.

Influenza-specific antibody titers and SDS-PAGE analysis of IgGs purified from naïve and infected ferrets. A, influenza-specific hemagglutinin inhibition (HAI) titers in pooled sera collected from four ferrets before (naïve) or after infection (infected) with H3N2 A/Hong Kong/4801/2014 (HK/4801). B, HK/4801 HA-specific antibody titers in IgGs purified from pooled sera of four naïve or four infected ferrets. C, SDS-PAGE analysis of purified IgGs from naïve and infected ferrets along with nonspecific mouse monoclonal IgG and rabbit polyclonal IgG under both nonreducing and reducing conditions. MW, molecular weight. D, purified ferret IgGs were denatured, treated with PNGase F to remove all N-glycans or Endo H to cleave at the inner bichitose of high-mannose and hybrid N-glycans, and separated on SDS-PAGE under reducing conditions. As controls, the enzymes Endo F and Endo H were also loaded on SDS-PAGE, and electrophoresis was run to help with identification of bands in the treated samples.