Abstract: A method and devices for rapid cooling of small biological samples by plunging them in a cryogenic liquid, such as liquid nitrogen, or contacting them with a cryogenic metal surface, reduce or eliminate the cold gas layer that forms above the liquid cryogens or cryogenic surfaces, producing an abrupt transition from ambient (e.g., room) temperature to the cryogen temperature as the sample enters the liquid or contacts the surface. To reduce or eliminate the effects of the cold gas layer, a flow of warm dry gas can be directed along the plunge path, for example. By removing this cold gas layer, cooling times for a 10 micron sample (the size of single cells and the smallest protein crystals now used protein crystallography) will decrease to ˜0.001 s.

Abstract: A method and devices for rapid cooling of small biological samples by plunging them in a cryogenic liquid, such as liquid nitrogen, or contacting them with a cryogenic metal surface, reduce or eliminate the cold gas layer that forms above the liquid cryogens or cryogenic surfaces, producing an abrupt transition from ambient (e.g., room) temperature to the cryogen temperature as the sample enters the liquid or contacts the surface. To reduce or eliminate the effects of the cold gas layer, a flow of warm dry gas can be directed along the plunge path, for example. By removing this cold gas layer, cooling times for a 10 micron sample (the size of single cells and the smallest protein crystals now used protein crystallography) will decrease to ˜0.001 s.