Page 1429 - Veterinary Immunology, 10th Edition

FIG. 42.25 Immunoelectrophoresis of pig serum showing the lines
VetBooks.ir also Fig. 15.23.)
of precipitation produced by some of the major serum proteins. (See

If, instead of being permitted to passively diffuse into agar-

containing antiserum as in the radial immunodiffusion technique,
the antigen is driven into the antiserum agar by electrophoresis, the
ring of precipitation around each well becomes deformed into a
rocket shape. The length of the rocket is proportional to the amount

of antigen placed in each well. This technique is called rocket
electrophoresis.

Titration of Antibodies

Although the simple detection of antibodies or antigen is sufficient
for many purposes, it is usually desirable to quantitate the reaction.
One way of measuring specific antibody levels is by titration. The
serum under test is diluted in a series of decreasing concentrations

(Fig. 42.26). Each dilution is then tested for activity. The reciprocal
of the highest dilution giving a positive reaction, called the titer,
provides an estimate of the amount of antibody in that serum.

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