Use of whole blood samples preserved in DNA lysis buffer for serological detection of avian malaria in Hawaiian forest birds

Abstract

Two buffers that are commonly used to preserve whole blood for polymerase chain reaction (PCR) diagnostics, tris-ethylenediaminetetraacetic acid (TEN) and tris-sodium dodecyl sulfate-ethylenediaminetetraacetic acid (SDS-EDTA), were evaluated to determine whether they can also be used to preserve blood for serological studies to detect antibodies to avian malaria. TEN buffer had no effect on antibody binding as measured by enzyme-linked immunosorbent assay (ELISA) or Western blotting. By contrast, the SDS-EDTA buffer completely abolished all antibody binding. Efforts to restore binding by dialysis and concentration of the samples were not successful. Addition of sodium dodecyl sulfate (SDS) and Proteinase K to samples preserved in TEN buffer was also evaluated, because this treatment is sometimes used to render samples non-infectious prior to shipping. This treatment abolished all antibody binding by both ELISA and Western blotting. TEN buffer appears to be good for preserving whole blood samples for both PCR and serological studies, making it possible to simultaneously preserve blood samples for both PCR and serological diagnostic tests in a single tube.