A custom-built controlled-rate freezer for small sample cryopreservation studies.

A Medrano; J Anderson; J D Millar; W V Holt; P F Watson

PubMed · 12522510

A custom-built controlled-rate freezer for small sample cryopreservation studies.

A Medrano·J Anderson·J D Millar·W V Holt·P F Watson

Abstract

A custom-built controlled-rate freezing machine is described. It operates by automatically raising and lowering the sample carrier in a static column of liquid nitrogen vapour. It is controlled by a computer-assisted thermocouple feedback system that operates a stepper motor driving the sample carrier. The cooling protocol is divided into three phases: cooling from +5 to -5 C, initiation of ice nucleation, and cooling from -5 to -80 C. Experiments are described to validate the device over a range of different cooling rates. A freezing protocol is established to cool samples in plastic straws over a range of rates up to 80 C/min, with rapid and consistent absorption of the latent heat.

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Animals Cryopreservation Equipment Design Freezing Male Semen Preservation Swine Journal Article Research Support, Non-U.S. Gov't

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A Medrano, J Anderson, J D Millar, W V Holt, P F Watson. A custom-built controlled-rate freezer for small sample cryopreservation studies.. https://pubmed.ncbi.nlm.nih.gov/12522510/

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