TllE BL001) GROrJPS OF MARINE ANIMALS
117
A valuable discovery, put to practical use independently by
Sprngue, Suzuki, and others is thc finding that suitable blood samples
Cali be taken from the hcart or gill arches of fish that are already dead,
following thc ‘ I rule of thumb ” that the fish still be marketable as
food and have not boen frozen. The blood of whales is taken after
death during fiensing. The use of blood obtained post-mortem makes
it possible to obtain samples from the catch of fishermen after landing
and greatly enlarges the number of samples available. Again, specifics
vary with respect to obtaining good saniples.
Once obt,ainccl blood samples can either bc placed in tubes and
allowed to clot, or placcd in anticoagulant. Erythrooytes are given
the conventional I ‘ three times ” washing by centrifugation as needed,
using an appropriate isotonic saline solution. The cells of many marine
fish handle well in 1.5% sodium chloride, but this is not always the
case. For exnmple, salmon and trout crythrocytcs appcar to keep best
in Alysever’s solution, and a satisfactory solution for the handling of
anchovy red cells has only just been found (Vrooman personal communication). Green and Hoffman (1953) have published a study of
isotonic solutions for the erythrocytes of some marine fishes, and the
reader’s attention is called to the observation by Ball (3933) of the
hemolytic action of traces of silver in sodium chloride for the cells of
some fish.
C. Preservation of samples
It has not been found practical or necessary to observe sterile
precautions while collecting samples, although care fihould be taken
to avoid contamination with body fluids, extcrnal mucus, and foreign
materials in general. Antibiotics arc sometimes added to the collecting
solutions, and refrigeration must be resorted to at all times. The
erythrocytes of many species can be kept for several weeks. Recent
experiments reported by Fujii et al. (1062) suggest that nucleic acid
hydrolysates added to blood samples may enhance preservation, but
more work needs to be done in this area. While fresh cells are preferred,
erythrocytes can be kept frozen in a useful condition for several months
by collecting whole blood into a solution of glycerol-citrate (Cushing
et d., 1957, 1059) without quick freezing and placing them a t -220°C.
Both cells and serum antibodies are recovered by thawing aliquots
of the samples and dializing them for 4 h or RO against isotonic saline.
This method has bccn used succcssfully in several studies, notably on
cetaceans and tunas, and offers promise for further development.
(Noteworthy, however, is the point that salmon red cells are not
recoverable by dialysis, but must be retrieved by step-wise suspension
117
A valuable discovery, put to practical use independently by
Sprngue, Suzuki, and others is thc finding that suitable blood samples
Cali be taken from the hcart or gill arches of fish that are already dead,
following thc ‘ I rule of thumb ” that the fish still be marketable as
food and have not boen frozen. The blood of whales is taken after
death during fiensing. The use of blood obtained post-mortem makes
it possible to obtain samples from the catch of fishermen after landing
and greatly enlarges the number of samples available. Again, specifics
vary with respect to obtaining good saniples.
Once obt,ainccl blood samples can either bc placed in tubes and
allowed to clot, or placcd in anticoagulant. Erythrooytes are given
the conventional I ‘ three times ” washing by centrifugation as needed,
using an appropriate isotonic saline solution. The cells of many marine
fish handle well in 1.5% sodium chloride, but this is not always the
case. For exnmple, salmon and trout crythrocytcs appcar to keep best
in Alysever’s solution, and a satisfactory solution for the handling of
anchovy red cells has only just been found (Vrooman personal communication). Green and Hoffman (1953) have published a study of
isotonic solutions for the erythrocytes of some marine fishes, and the
reader’s attention is called to the observation by Ball (3933) of the
hemolytic action of traces of silver in sodium chloride for the cells of
some fish.
C. Preservation of samples
It has not been found practical or necessary to observe sterile
precautions while collecting samples, although care fihould be taken
to avoid contamination with body fluids, extcrnal mucus, and foreign
materials in general. Antibiotics arc sometimes added to the collecting
solutions, and refrigeration must be resorted to at all times. The
erythrocytes of many species can be kept for several weeks. Recent
experiments reported by Fujii et al. (1062) suggest that nucleic acid
hydrolysates added to blood samples may enhance preservation, but
more work needs to be done in this area. While fresh cells are preferred,
erythrocytes can be kept frozen in a useful condition for several months
by collecting whole blood into a solution of glycerol-citrate (Cushing
et d., 1957, 1059) without quick freezing and placing them a t -220°C.
Both cells and serum antibodies are recovered by thawing aliquots
of the samples and dializing them for 4 h or RO against isotonic saline.
This method has bccn used succcssfully in several studies, notably on
cetaceans and tunas, and offers promise for further development.
(Noteworthy, however, is the point that salmon red cells are not
recoverable by dialysis, but must be retrieved by step-wise suspension