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BioFX
Fish Gelatin Blocks and
Diluents |
BioFX Laboratories Fish Gelatin
blocks and diluents contain 5% type A
fish gelatin and are supplied as
concentrates. Fish gelatin is
produced from the skin of deep water
fish. This extra-cellular
glycoprotein is an antifreeze
protein varying somewhat in
structure from species to species.
However, the best known antifreeze
protein consists of a polypeptide
backbone of a recurring tripeptide
unit.
Antifreeze proteins depress the
freezing point of water because they
inhibit the formation of ice
crystals. A combination of
antifreeze proteins and high
concentrations of sodium chloride
further depress the freezing point.
Because the gel point is lower than
other animal gelatin, fish gelatin
is more suitable for frozen or
refrigerated products. For
coating applications, the high
molecular weight produces a tougher
film than standard gelatin.
BioFX Fish Gelatin Buffers
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Borate Buffered Saline (BBS),
working pH range of 8.0 ±
0.2
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Borate Buffered Saline
(BBS)/Glycerol, working pH range
of 8.0 ± 0.2
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Imidazole Buffered Saline
(IBS), working pH range of 7.0 ±
0.1
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Tris Buffered Saline (TBS),
working pH range of 7.6 ±
0.1
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Phosphate Buffered Saline
(PBS), working pH range of 7.4 ±
0.1
BioFX Granulated Fish Gelatin
Granulated fish gelatin should be
used to make a solution of fish
gelatin not greater than 5%.
The percentage is dependent upon the
desired application and preference.
Notes Regarding Biological Buffers
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May specifically stimulate or
depress enzyme activity
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May interfere or react with
substrates, inhibitors or
cofactors
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Non-specifically they may
exert effects due to their ionic
strength
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Concentrations should be kept
as low as possible and maintain
pH constancy
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The medium should be adjusted
by adding appropriate inorganic
and organic ions to simulate
physiological conditions
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Borate Buffered Saline (BBS)
should not be used in the
presence of polyols, including
carbohydrates and their
derivatives with which they may chelate; BBS has a high
bacteriocidal effect; the use of
BBS in gel electrophoresis can
result in spreading of the bands
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Tris Buffered Saline (TBS),
pH 7.6, is a poor buffer below
pH 7.5 and the pH can fall more
than 1 pH unit in warming from 0°C
to 37°C;
TBS has the disadvantages of its
reactivity as a primary amine
and its appreciable solubility
in organic solvents which can
lead to an accumulation in the
biological phase of a reaction
system; to avoid complex
formation with ionic species
such as calcium and magnesium in
blood, Tris buffers are
preferable over phosphate
buffers
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Phosphate is a poor buffer
above pH 7.5; phosphate buffer
should not be used in assays
where competition for phosphate
groups, or complex formation
with a metal ion is essential
for the enzyme activation;
phosphate ions will inhibit
carboxypeptidiase, carboxylase,
urease, muscle diaminase,
formase and phosphoglucomutase
“It is
impossible even to guess how many
exploratory experiments have failed,
how many reaction rates have been
depressed and how many processes
have been distorted because of
imperfections of the buffers
employed.”
Norman Good, et al.
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