A method is disclosed for cryopreserving living animal cells in
immunoisolation membranes, including: (1) cutting out a living organ from
an animal, (2) digesting the cutout organ into the discrete living animal
cells and separating the discrete cells, (3) suspending the separated
cells in a solution of sodium chloride containing sodium alginate and
collagen, (4) forming microcapsules of the living animal cells by using
the resulting suspension, (5) forming immunoisolation membranes around
outer surfaces of the microcapsules of the living animal cells by
covering the outer surfaces with alginate-(poly-L-lysine) and thereby
obtaining the living animal cells enclosed in the immunoisolation
membranes, (6) suspending the resulting living animal cells enclosed in
the immunocapsules in a cell damage-preventing solution, and (7)
immediately freezing the thus obtained suspension with liquid nitrogen.