This work is centred on the measurement of serum proteins
and in particular, albumin, in three species of domestic animals,
bovine, ovine and equine. The main methods of protein estimation
are reviewed on a historical basis and the various modifications
and improvements to each are discussed. During the course of the
discussion emphasis is given to the development of methods of
protein fractionation by electrophoresis, by the binding of various
indicator dyes to albumin and to the results obtained with animal
Although investigated recently in the medical field, very
little attention has been paid in the veterinary field to the
observation that bromocresol green (B.C.G.) dye is not bound
entirely specifically by albumin and that it also undergoes an
additional, time dependent reaction with certain other serum
globulins. Comparisons between human serum albumin results by
this dye-binding method and more specific techniques have shown
that albumin levels by the 'immediate' ( <.30 secs.) reaction wdth
B.C.G. dye are the most accurate. Only one group of veterinary
research workers have employed this reaction time when investigating
albumin levels in animal serum. The degrees of difference between
albumin levels obtained using the ’immediate' and the originally
described 10 minute B.C.G. reactions however, have not been
demonstrated and part of this work is devoted to the identification
of such differences. The effect of using non-specific albumin
standards and the reaction of specific purified globulin or albuminfree serum with B.C.G. dye is also investigated.
The remainder of this work is devoted to various aspects
f the electrophoretic behaviour of serum proteins and the
ecognition of the fractions which are clearly identifiable after
garose gel electrophoresis.
The main findings of this work were:-
(a) There was a positive difference in albumin levels
between those obtained by the 'immediate' and by the
10 minute B.C.G. reactions in the three species.
The widest of -these differences was observed when
bovine serum was analysed.
(b) Only albumin values obtained by the 'immediate' B.C.G.
reaction were in good agreement with a more specific
method of albumin measurement.
(c) Electrophoretic albumin values were also in good
agreement with those by the 'immediate' B.C.G. reaction.
(d) Equivalent amounts of purified albumin of each species
did not react identically with the dye and the use of
albumin standards in the B.C.G. method which were not
species specific led to statistically significant
discrepancies in albumin results.
(e) Purified gamma globulin of each species did not
react with B.C.G. dye, but other globulins did, although
unlike albumin, not on a weight for weight basis. The
reactivities of equivalent amounts of alpha and beta
globulins of each species appeared not to be identical.
(f) A set of normal serum protein values was determined
for each species using the main methods described in this study