from The American Heritage® Dictionary of the English Language, 4th Edition
- n. An antibody or product of complement activation in blood serum that causes bacteria or other foreign cells to become more susceptible to the action of phagocytes.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Any antibody that causes an invading species to be more susceptible to phagocytosis
from The Century Dictionary and Cyclopedia
- n. A hypothetical substance, present in blood-serum, upon which the phagocytic action of the leucocytes is dependent.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. an antibody in blood serum that attaches to invading microorganisms and other antigens to make them more susceptible to the action of phagocytes
I call opsonin, goes on in the system by ups and downs -- Nature being always rhythmical, you know -- and that what the inoculation does is to stimulate the ups or downs, as the case may be.
The "opsonin," or "relish," is something exuded into or produced in the blood fluid when the attacking microbe arrives.
In the absence of the relish (the Greek word for it used by Sir Almroth Wright, its discoverer, is "opsonin"), the eater-cells are sluggish -- too sluggish -- in their work.
Because of this characteristic, it has been called opsonin by Wright and bacteriotropin by Neufeld.
Wright, who has been largely responsible for developing this argument, insists on the subordinate role of the white corpuscles that follow blindly the opsonin lead.
This opsonin of normal serum is very labile, being rapidly destroyed at 55° C.; that is, a serum heated at this temperature has practically no greater effect in aiding phagocytosis than normal salt solution has.
In the case of the latter animal the serum [v. 03 p. 0180] contains an opsonin which leads to phagocytosis of the bacillus, and the latter is then destroyed by the leucocytes.
In the method for demonstrating opsonin about to be described, a comparison is made between the opsonic "power" of the pooled serum and the specific serum.
The three most important of the antibodies referred to which can be demonstrated with a certain amount of facility are agglutinin, opsonin and bacteriolysin; and the methods of testing for these bodies will now be considered.
To inject a vaccine into a patient without first testing his opsonin is as near murder as a respectable practitioner can get.