First the "O" antigen type is determined based on oligosaccharides associated with lipopolysaccharide. Then the "H" antigen is determined based on flagellar proteins (H is short for the German Hauch meaning "breath" or "mist"; O stands for German ohne meaning "without").
- What does the O antigen do?
- What is the meaning of H antigen?
- What is H antigen in bacteria?
- What is somatic O antigen?
- Where is the O antigen found?
- Are there O antigens?
- What is flagellar antigen?
- What blood type is Bombay Blood?
- What does blood antigen mean?
- Does O blood group have H antigens?
- What is O and H in widal test?
- How do you detect antigens?
What does the O antigen do?
The O antigen is an extremely variable surface polysaccharide of Gram-negative bacteria. This variation is thought to allow the various clones of a species each to present a surface that offers a selective advantage in the niche occupied by that clone.
What is the meaning of H antigen?
Also known as substance H, H antigen is a precursor to each of the ABO blood group antigens, apparently present in all people except those with the Bombay Blood phenotype (see hh blood group) Histocompatibility antigen, a major factor in graft rejection.
What is H antigen in bacteria?
Medical Definition of H antigen
: any of various antigens associated with the flagella of motile bacteria and used in serological identification of various bacteria. — called also flagellar antigen.
What is somatic O antigen?
The O antigen, also called somatic antigen, is the polysaccharide portion of the outer membrane liposaccharide and the H antigen, also called flagellar antigen, is the protein flagellin that makes the filaments of the bacterial flagellum.
Where is the O antigen found?
Abstract. The O antigen, consisting of many repeats of an oligosaccharide unit, is part of the lipopolysaccharide (LPS) in the outer membrane of Gram-negative bacteria.
Are there O antigens?
The ABO system
blood group O – has no antigens, but both anti-A and anti-B antibodies in the plasma. blood group AB – has both A and B antigens, but no antibodies.
What is flagellar antigen?
Flagellar (H) Antigens
Flagellar antigens are heat-labile proteins. Mixing salmonella cells with flagella-specific antisera gives a characteristic pattern of agglutination (bacteria are loosely attached to each other by their flagella and can be dissociated by shaking).
What blood type is Bombay Blood?
This required blood donation. But the youngster has a very rare blood type. His blood is not O, A, B, or AB, but a special type called (hh)- a rare one first discovered in Bombay in 1952, and hence christened as Bombay Blood.
What does blood antigen mean?
An antigen is any substance to which the immune system can respond. For example, components of the bacterial cell wall can trigger severe and immediate attacks by neutrophils. If the immune system encounters an antigen that is not found on the body's own cells, it will launch an attack against that antigen.
Does O blood group have H antigens?
Depending upon a person's ABO blood type, the H antigen is converted into either the A antigen, B antigen, or both. If a person has blood group O, the H antigen remains unmodified. Therefore, the H antigen is present in the highest amounts in blood type O and in the least amounts in blood type AB.
What is O and H in widal test?
Serology. The traditional Widal test measures antibodies against flagellar (H) and somatic (O) antigens of the causative organism. In acute infection, O antibody appears first, rising progressively, later falling and often disappearing within a few months. H antibody appears a little later but persists for longer.
How do you detect antigens?
Direct antigen detection methods have been described for BVDV using blood and a variety of fresh, frozen, or fixed tissues. These methods include immunohistochemistry (IHC), antigen capture enzyme-lined immunosorbent assay (ELISA) (ACE), and immunofluorescence.