The detection of antibodies against foot-and-mouth disease virus (FMDV) in filter paper eluates from pig sera or whole blood by ELISA.
The use of pig blood samples dried on paper discs for the detection of antibodies against FMDV by the liquid phase blocking ELISA has been evaluated. The average volume of whole heparinised blood required to fully saturate 6.0 mm discs was 7.65 microliters (range 7.2 to 8.1; variation = 0.24, P = 0.05). When 200 clinically healthy animals were assessed by virus neutralisation (VN) titres up to 1/22 were recorded against types O, A and C, 97% being 1/11 or less. Using ELISA, results were more skewed. Overall, 91% showed titres of 1/32 or less, and there were occasional high non-specific reactors with types O and A. Using small groups of sera from experimental animals, a VN titre of 1/16 was found to be equivalent to an ELISA titre of approximately 1/100 (log10 2.0 +/- 0.2) with type O and 1/56 (log10 1.75 +/- 0.1) for type A. Although some loss in sensitivity from disc dried sera was found in selected negatives on testing at a single dilution of 1/32, sera from vaccinated animals with VN titres of 1/16 to 1/708 all gave strong positive results. A monoclonal antibody (Mab) assay was successfully developed to detect different swine anti-FMDV antibody isotypes.
Armstrong
R M
RM
A.F.R.C. Institute for Animal Health, Pirbright, U.K.
Crowther
J R
JR
Denyer
M S
MS
D000818:Animals; D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral / Q000032:analysis*; D005537:Aphthovirus / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005536:Foot-and-Mouth Disease / Q000175:diagnosis*; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D009500:Neutralization Tests; D013552:Swine
D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M