Lyophilization
Lyophilization process
the
cell
suspensions
are
placed
in
small
vials
which
are
then
frozen
by
immersing
in
a
mixture
of
dry
ice
and
acetone
or
liquid
nitrogen.
The
vials
are
then
evacuated
and
dried
under
vacuum,
sealed
and
stored
at
a
low
temperature.
This
method
provides
long
term
culture
survival
without
a
change
in
any
characteristic.
Also,
lyophilized
cultures
take
little
space
for
storing.
Although
cultures
can
be
stored
for
long
periods
by
this
method,
viability
depends
to
a
very
great
extent
oil
the
quality
of
glass
vials
used.
It
has
been
found
that
loss
of
vacuum
during
storage
leads
to
inactivation
of
cultures.
