| 摘要 |
A process for preserving animal tissue cells comprises (1) contacting such cells with a protective additive which reduces cell damage during subsequent freezing, (2) cooling the cell-protective additive combination to freezing point and then making the liquid to solid phase change in less than 10 minutes (3) further cooling the solidified cells to -50 DEG C. at a rate not more than 3 DEG C. per minute, and (4) further cooling the frozen cells and maintaining the frozen cells at a temperature below -75 DEG C. The protective additive may be glycerol, ethylene glycol, an aldose, a ketose, a polysaccharide, polyvinyl pyrolidone, dimethyl sulphoxide, mannitol, urea or animal serum. The protective additive may be dispersed in a liquid medium containing nutrients for the cells (e.g. amino acids, saccharides, inorganic salts, proteins, vitamins and animal serum). The protective additive may be perfused through an organ before removal from the body, or the organ, aggregate of cells or individual cells may be suspended in or have poured thereover the protective additive containing medium. The tissue may be suspended in a medium (e.g. Tyrode's or Hank's) before being mixed with the additive containing medium. The cells can be cooled by immersion in refrigerants or by passing cold gas over them. Anticoagulants may be mixed with the cell aggregates before treatment. The cells may be those in bone marrow and tissue of kidneys, liver, heart, spleen and lungs. |
