Serological reactions Reaction of antigen and antibody in laboratory conditions in different (stated) environment Antigen – substance with ability to activise immune system to specific antibodies production. Non self substance. Immunogenicity. Protective antibodies Antigenic determinants – areas of microorganism with a structure eliciting the antibodies production Specificity of antigen – determined by production of antibodies, that reacts only with it. Non specific antigens – heterofil – if antibodies agains them react with other antigens

Antibodies In blood serum of immunised annimals there are specific proteins – immuneglobulins, that bind antigens causing their production (behring, Kitaso, 19 th century) Serum – liquid that will remain at the top of the tube after centrifugation of coagulated blood Plasma – liquid that remains at the toop of tube after centrifugation of not coagulated blood Antiserum – serum with specific antibodies Function of antibodies – to bind specifically antigen, neutralise its function via other reactions that are activised by the antigen antibody binding (complement activation....)

Serological reaction Reaction of antigen with specific antibody depends on the type of antigen – formes immunocomplexes of different quality *corpuscular antigens –(microorganism, erytrocytes) = agglutination *soluble antigens – small imunocomplexes – in solution or precipitation

Electrophoresis of proteins Alfa, beta, gama fraction Immunoglobulines – 5 classes IgG, IgA, IgM, IgD, IgE - types of heavy chains: mi, delta, gama, alfa, epsilon – subclasses IgG1, IgG2, IgG3, IgG4,, types of light chains – kappa, lambda, subtypes : lambda 1,2,3,4,

Antibodies production - dynamics Acute antibodies IgM Persistent antibodies IgG - protective First response IgM Booster effect second response Total antibodies

Serological reactions Agglutination – antigen + several dilution of serum = visible agglutination Latex agglutination – antibody bound on latex particles + Ag = big agglutination Precipitation – Ag+Ab = ring in the touch zone Immunediffusion – diffusion of Ag and Ab in agar. In the meeting point – precipitation ring Neutralisation – serum with antibodies can neutralise the activity of microorganisme in living model Hemagglutination – passive agglutination – ag is bound on the surface of RBC CF – complement fixation- Ag +Ab +C´+ Ery + antieryab – lysis ELISA, RIA, IFT

Reading of serological reactions Qualitative reaction – positive or negative (comparison with bordeline value) Quantitative reaction – titer of antibodies, or concentration Determination of total antibodies (CF,) – dynamics of antibody production – 2 samples in the interval of days. Results – titer of antibodies = 1:16(dilution )., 16(Titer – amount of antibodies in not diluted serum) Determination of immuneglobulin classes – IgA, igM – acute IgG – long lasting, protective, Results – in concentration of antibodies – g/l Confirmation of acute infection: Seroconversion – from negativity to positivity, fourfold increase of total antibody titer, or presence of IgM