Kh. Roed et al., IMMUNOASSAY AND PARTIAL CHARACTERIZATION OF SERUM TRANSFERRIN FROM ATLANTIC SALMON (SALMO-SALAR L), Fish & shellfish immunology, 5(1), 1995, pp. 71-80
Atlantic salmon (Salmo salar L.) serum transferrin was purified by riv
anol precipitation followed by anion exchange liquid chromatography an
d polyacrylamide gel electrophoresis. Transferrin was identified by ra
dio-iron and analysed by amino terminal sequencing. Electrophoresis sh
owed isoforms of transferrin both on native and denaturating polyacryl
amide gels. All isoforms had identical amino terminal sequences and si
alic acid linked to galactose. Removal of sialic acid groups by neuram
idase treatment of single and mixed transferrin isoforms revealed five
different charge forms suggesting the presence of up to four sialic a
cid residues on Atlantic salmon serum transferrin. Polyclonal and mono
clonal antibodies against salmon transferrin were produced and used in
an enzyme-linked immunosorbent assay (ELISA). The sensitivity of the
assay is high with the lowest detectable transferrin concentration bei
ng 0.5-1 ng ml-1. No cross activity of the assay with serum from horse
, rabbit or rainbow trout could be detected. The within-assay variabil
ities were 2.5 and 7% when assayed within and between dilutions of the
Atlantic salmon serum samples, respectively.