Cryogenic freezing of liquids

DETAILED DESCRIPTION An embodiment of the instant invention is a method of rapidly freezing and storing water or liquid samples without the use of cryoprotectants to minimize or eliminate damage from ice crystals or osmotic forces, allowing very high recovery rates upon thawing.
The liquid sample is transformed into very small drops which are contacted directly with a refrigerant which is at least partially solidified.
The refrigerant may be a solid undergoing a solid-to-liquid phase change, or a solid-to-gas phase change.
This method is especially useful for substances that are susceptible to ice crystal or osmotic damage, such as proteins, peptides, and other macromolecules.
A further embodiment of the invention is a method of stopping a chemical or biological reaction by rapidly freezing the reaction mixture through direct contact with a refrigerant which is at least partially solidified.
Molecular slowing occurs almost instantly, preserving the compounds in mid-reaction.
The various molecular steps of the reaction are frozen in place, and can be analyzed by studying the vitrified sample.
A further embodiment of the invention is to provide a method for lyophilizing chemical and biological compounds or compositions while retaining structural integrity.
Reconstitution of the substance will restore the original liquid sample with little or no damage.
Specific applications of this type of lyophilization include freeze dried foodstuffs (coffee, milk, juices, etc.
), medical supplies (vaccines, antibiotics, etc.
) and laboratory processes (protein extractions, molecular biology samples, etc.
).
An additional embodiment of the invention is a method for production of fine-grained or amorphous solids by direct deposition of a vapor substance onto a cryogenic gas which is at least partially solidified.
Another embodiment of the invention is an apparatus for rapid freezing a liquid sample.
The apparatus comprises a means for driving the liquid sample directly onto a refrigerant which is at least partially solidified