1. Acid stability of the HA protein of clade 2. 3. 4
Acid stability of the HA protein of clade A(H5N8) and A(H5N2) viruses.
Acid stability of the HA protein of clade A(H5N8) and A(H5N2) viruses. (A) Acid-induced hemolysis was determined using cRBC. The viruses were bound to cRBC, and hemolysis was induced by treatment with different pH-adjusted buffers. The corrected optical density (C.O.D.) measures the amount of hemoglobin released after fusion. The results are shown as means ± standard deviations from 4 replicates at the indicated pH value. The curves were fitted to an asymmetrical (five-parameter) regression model (dotted line), and the pH50 values were determined as the point at which a 50% change between maximum and baseline was observed. (B) Acid-induced inactivation of A(H5N8) and A(H5N2) viruses. The viruses were treated with different pH-adjusted buffers, and the remaining infectious virions were titrated by TCID50. The results are shown as means ± standard deviations from 2 replicates at the indicated pH value. The curves were fitted to an asymmetrical (five-parameter) regression model (dotted line), and the pH50 values were determined as the point at which a 50% change between maximum and baseline was observed.
Bryan S. Kaplan et al. mSphere 2016; doi: /mSphere