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Many amoeba can be easily
stored as they create their own protective casing around themselves in
the form of the cyst. Others of course do not and these tend to be
less easy to maintain both in long term culture and as frozen
stocks. The availability of liquid nitrogen for rapid freezing has
greatly helped in the storage of amoeba and most can be stored satisfactorily
using a combination of rapid freezing with liquid nitrogen and storage
at below -20oC.
This
method (John et al, 1994), is
for the long-term storage of amoebal strains at -70oC.
1) Take
1ml of dense culture of amoebae and spin down.
2) Remove
supernatant and take up in 100µl of freezing media
3) Acclimatise
for 30 minutes at room temperature.
4) Place
in -20oC freezer for 1 hour.
4) Place
in -70oC freezer.
Freezing Medium
Working
Concentration
500mls
12% dimethylsulphoxide
60mls
20% Heat Inactivated calf serum*
100mls
Axenic medium (or other)
340mls
*
Heat inactivate by warming to 55 oC for 1 hour.
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