Much of our previous work with murine sera showed few if any proteins with a pI 7 to be reactive with sera from LVS immunized BALB/c or C57/BL6 mice.
Given the limited amounts of sera available from clinical samples, therefore, the analyses in this study were initially confined to pH 4–7 .
One serum sample from each study set was also screened against antigen separated in the pH range 6–11.
Immunoblotting was carried out according to methods previously published by others and described in our own work .