Antigens antibody inducers

Aqueous extracts of cotton dust and cotton bract induced the formation of specific precipitating antibodies in rabbits. The antisera cross-reacted with both extracts as well as with extracts of cotton stem, leaf, and burr, baled cotton and gin trash. Cross-reactivity was also demonstrated with extracts of flax, soft hemp, sisal, and jute. No antigen-antibody reaction was obtained with extracts of cottonseed hulls, cottonseed proteins, noncontami-nated cotton lint, or house dust. No reaction was obtained between the antisera to dust and several connmercial preparations of bacterial lipopolysac-charides believed to be present in cotton dust. 

Immunosensors can be classified into two broad categories non-labelled and labelled. Non-labelled immunosensors are designed in such a way that the immunocomplex i.e. the antigen-antibody complex) is directly determined by measuring the physical changes induced by the complex formation. In contrast, labelled immimosensors include a sensitively detectable label, so the inmumocomplex is determined by measuring the label. 

Histamine is released from mast cells in antigen-antibody reactions, as in anaphylaxis and allergy, which are the most widely known physiological reactions to histamine. However, these potentially fatal reactions are not caused by histamine alone. Other agents present in mast cells, such as serotonin, acetylcholine, bradykinin (a nonapeptide), and a slow-reacting substance or leukotriene (see chapter 8) also contribute. In the stomach, where histamine induces acid secretion, its release seems to be regulated by the peptide hormone pentagastrin. 

Antibodies or immunoglobulins (these terms are interchangeable) are glycoproteins which bind specifically to the antigens that induced their formation and each one is formed as a unique response to that particular antigen. In the body they are present in body fluids and certain types of cell. Serum, the fluid that separates when blood is allowed to clot, contains no cells but it does contain the immunoglobulins which can be separated electrophoretically. They have different molecular weights and... 

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