Detection of serum immunoglobulins in wild birds by direct ELISA: a methodological study to validate the technique in different species using antichicken antibodies

Abstract

Summary This study presents an easy protocol to measure the amount of immunoglobulins from the blood serum of different bird species in the wild (Ficedula hypoleuca Pallas, Parus caeruleus L., Lanius meridionalis Temminkck, Lanius collurio L., Athene noctua Scopoli and Falco tinnunculus L.) by direct enzyme‐linked immunosorbent assay, ELISA using commercial antichicken antibodies. Additionally, the ELISA technique is validated for detecting serum immunoglobulins by means of other electrophoretic (sodium dodecyl sulphate polyacrylamide gel electrophoresis, SDS‐PAGE, and native electrophoresis) and immunological (Western blot) methods. The results by Western blot show that the commercial antibody recognized proteins with apparent molecular weight according to heavy and light chains of immunoglobulins. Both ELISA and Western blot data were correlated, implying that the commercial antibody bound to immunoglobulins and not to other proteins or ELISA plates. Densitometric data achieved by SDS‐PAGE and native electrophoresis were only correlated in some species indicating a problem in detecting clearly the heavy and light chains, and γ‐globulin fraction, respectively. It is concluded that the proposed protocol is easy to carry out and may be used to detect total serum immunoglobulins from most bird species.