- in Rh-v person , this Ag not found:
antigen:
Antigen, substance that is capable of stimulating an immune response, specifically activating lymphocytes, which are the body’s infection-fighting white blood cells.
In general, two main divisions of antigens are recognized: foreign antigens (or heteroantigens) and autoantigens (or self-antigens).
Foreign antigens originate from outside the body. Examples include parts of or substances produced by viruses or microorganisms (such as bacteria and protozoa), as well as substances in snake venom, certain proteins in foods, and components of serum and red blood cells from other individuals.
Autoantigens, on the other hand, originate within the body.
Normally, the body is able to distinguish self from nonself, but in persons with autoimmune disorders, normal bodily substances provoke an immune response, leading to the generation of autoantibodies.
An antigen that induces an immune response—i.e., stimulates the lymphocytes to produce antibody or to attack the antigen directly—is called an immunogen.
- Z.N stain use for diagnose:
Mycobateria:
Mycobacteria are Gram-positive, catalase positive, non-motile, non-spore forming rod-shaped bacteria (0.2–0.6 μm wide and 1.0–10 μm long).
The colony morphology of mycobacteria varies with some species growing as rough or smooth colonies. Colony colour ranges from white to orange or pink.
Most mycobacteria are aerobic organisms, although some species are microaerophilc.
The cell walls of mycobacteria are very thick and consist of four layers.
The innermost layer is composed of peptidoglycan and the others of lipids. The presence of lipid provides the bacteria with resistance to acid and alkaline environments and renders the cells relatively impermeable to various basic dyes, which need to be combined with phenol to allow penetration of the cell wall.
The cell wall composition renders mycobacteria hydrophobic, and as a result these bacteria tend to grow in aggregates that ‘float’ on the surface of liquid media. Detergents, such as Tween® 80 can be added to culture media to disperse the organisms.
Certain mycobacteria, including Mycobacterium paratuberculosis (MAP), can shed their cell walls, forming spheroplasts which are not detected using the acid-fast stain test.
antigen:
Antigen, substance that is capable of stimulating an immune response, specifically activating lymphocytes, which are the body’s infection-fighting white blood cells.
Foreign antigens originate from outside the body. Examples include parts of or substances produced by viruses or microorganisms (such as bacteria and protozoa), as well as substances in snake venom, certain proteins in foods, and components of serum and red blood cells from other individuals.
Autoantigens, on the other hand, originate within the body.
Normally, the body is able to distinguish self from nonself, but in persons with autoimmune disorders, normal bodily substances provoke an immune response, leading to the generation of autoantibodies.
An antigen that induces an immune response—i.e., stimulates the lymphocytes to produce antibody or to attack the antigen directly—is called an immunogen.
- Z.N stain use for diagnose:
Mycobateria:
Mycobacteria are Gram-positive, catalase positive, non-motile, non-spore forming rod-shaped bacteria (0.2–0.6 μm wide and 1.0–10 μm long).
The colony morphology of mycobacteria varies with some species growing as rough or smooth colonies. Colony colour ranges from white to orange or pink.
Most mycobacteria are aerobic organisms, although some species are microaerophilc.
The cell walls of mycobacteria are very thick and consist of four layers.
The innermost layer is composed of peptidoglycan and the others of lipids. The presence of lipid provides the bacteria with resistance to acid and alkaline environments and renders the cells relatively impermeable to various basic dyes, which need to be combined with phenol to allow penetration of the cell wall.
The cell wall composition renders mycobacteria hydrophobic, and as a result these bacteria tend to grow in aggregates that ‘float’ on the surface of liquid media. Detergents, such as Tween® 80 can be added to culture media to disperse the organisms.
Certain mycobacteria, including Mycobacterium paratuberculosis (MAP), can shed their cell walls, forming spheroplasts which are not detected using the acid-fast stain test.
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Clinical Pathology