Process and apparatus for freezing living cells
AssigneeHelmholtz-Institut fur Biomedizinische Technik
InventorsMax W. Scheiwe, Gunter Rau
Life of this patent
Estimating the term…
Abstract
The process for freezing cell suspensions by locating the suspension in a freezing chamber and simultaneously monitoring the temperature of the suspended cells and of the chamber. The cooling of the chamber is regulated at predetermined rates in response to given temperature levels of the sample. The cooling chamber includes a fan, a heater, and a source of refrigerant. The process includes the steps of selectively decreasing and increasing the temperature of the freezing chamber responsive to predetermined temperature points on the freezing curve of the cell sample.
Claims10
Apparatus for freezing cell suspension samples comprising a freezing chamber having an inlet connected to a source of refrigerant media, a freezing section located downstream of said inlet for locating a plurality of separately packaged samples to be frozen, a heating unit located within said chamber downstream of said freezing section, and a fan located within said chamber between said heating unit and said inlet, a first sensor for determining the temperature of said freezing section, and a second sensor for determining the temperature of at least one of said samples located therein, and control means responsive to said first and second sensors for determining the velocity of phase transition of the solid-liquid boundary in the freezing cell suspension, the actual freezing temperature of the cell suspension frozen, and the supercooling of the freezing cell suspension, means for generating a freezing curve of the chamber independent of the number of samples within said chamber, and means for regulating the flow of refrigerant, the heating unit and said fan in a predetermined program responsive to the instantaneous temperature of the sample, the control means using defined points of the sample temperature to regulate the operation of said fan, heater and refrigerant inlet to freeze and maintain said samples in accordance with the freezing curve generated.
Apparatus for freezing cell suspension samples comprising:
- a housing having walls defining therein an enclosed oval duct forming a continuously circulating passage, one section of said duct constituting a freezing section for the location of a plurality of separately packaged samples to be frozen and having,
- an inlet to said passage spaced from said freezing section, for the introduction of a refrigerant into said duct,
- a heating unit located in said duct between said inlet and said freezing section downstream of said freezing section for heating said refrigerant,
- a fan located in said duct between said inlet and said freezing upstream of said freezing section for moving said refrigerant through said freezing section,
- a first sensor for determining the temperature within said freezing section,
- a second sensor for determining the temperature within a selected one of said samples, and
- control means for regulating the flow of refrigerant, the operation of said heating unit and said fan responsive to said sensors in a predetermined program to effect the desired freezing of said samples.
Apparatus for freezing cell suspension samples comprising a housing having defined therein a freezing section, an inlet for the introduction of refrigerant into said freezing section, a heating unit for heating said refrigerant, a fan for moving said refrigerant through said freezing section, a first sensor for determining the temperature within said freezing section, a second sensor comprising a thermocouple detecting the velocity of the phase transition in the liquid-solid boundary of the selected sample, the actual temperature of the sample and any supercooling of the sample and control means for regulating the flow of refrigerant, the operation of said heating unit and said fan responsive to said sensors in a predetermined program to effect the desired freezing of said samples.
Dependencies are inferred from the claim text.