Inoculation

inoculation,

in medicine, introduction of a preparation into the tissues or fluids of the body for the purpose of preventing or curing certain diseases. The preparation is usually a weakened culture of the agent causing the disease, as in vaccination against smallpox; however, it may also be composed of antitoxins, which provide immunity themselves, or toxoids, which are proteins that stimulate the body to produce antitoxins (see immunity). Various forms of inoculation were used from ancient times in China, India, and Persia, but it remained for the English physician Edward Jenner in the late 18th cent. to demonstrate its feasibility to the Western world. The term inoculation is used also to refer to the introduction of certain substances into plant tissues or to the placement of microorganisms into culture media (for experimental or diagnostic purposes) or into the soil.

Inoculation

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

Inoculation

 

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).

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Inoculation

 

(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.

REFERENCE

Levi, L. I., and S. K. Kantenik. Liteinye splavy. Moscow, 1967.

A. A. ZHUKOV

inoculation

[i‚näk·yə′lā·shən]

(biology)

Introduction of a disease agent into an animal or plant to produce a mild form of disease and render the individual immune.

(metallurgy)

Treating a molten material with another material before casting in order to nucleate crystals.

(microbiology)

Introduction of microorganisms onto or into a culture medium.