Inoculation(redirected from inoculations)
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The process of introducing a microorganism or suspension of microorganism into a culture medium. The medium may be (1) a solution of nutrients required by the organism or a solution of nutrients plus agar; (2) a cell suspension (tissue culture); (3) embryonated egg culture; or (4) animals, for example, rat, mouse, guinea pig, hamster, monkey, birds, or human being. When animals are used, the purpose usually is the activation of the immunological defenses against the organism. This is a form of vaccination, and quite often the two terms are used interchangeably. Both constitute a means of producing an artificial but active immunity against specific organisms, although the length of time given by such protection may vary widely with different organisms. See Immunity, Vaccination
the introduction of live microorganisms, infective material, serum, or other substances into plant, animal, or human tissues, as well as into cultural media. The inoculation of a healthy person with a live causative agent of a disease (for example, vaccinia virus) produces a mild form of the disease and thereby develops immunity. Inoculation may be therapeutic (injection of specific serum for therapeutic purposes) or prophylactic (injection of immune serum or vaccine as a means of protection against a particular disease).
(of metals and alloys), the introduction of inoculants into molten metals and alloys. The addition of small quantities of inoculants sharply affects crystallization properties and, for example, leads to the formation of spherical or refined structural components and facilitates their even distribution throughout the principal phase. As a result of inoculation, alloys acquire a finer structure, which improves their mechanical properties. Inoculation is used in the production of cast iron and silumin ingots.
Inoculation is distinct from microalloying, in which an increase in the quantity of additive leads to ordinary alloying (without a clear boundary between the effects produced). In inoculation, an increase in the quantity of additive may be impossible (because of volatility or low solubility), inefficient, or harmful (overinoculation).
The phenomenon of liquid inoculation is sometimes observed upon the mixing of two different melts. An effect similar to inoculation may be produced by some types of physical treatment of molten metal—for example, in ultrasonic treatment and the application of an electromagnetic field.
REFERENCELevi, L. I., and S. K. Kantenik. Liteinye splavy. Moscow, 1967.
A. A. ZHUKOV