Sample warming research: Warming rates may be surprising
May 27, 2015
Good biological cryogenic practices tell us to store as cold as possible, minimize freeze-thaw cycles and always protect innocents from warming above Tg (the glass transition temperature, -135°C for H2O). But just how quickly do samples warm? Are there variables that speed or slow warming?
Dr. Matteo Salvetti, Sr. Product Engineer, presented data at ISBER 2015 which discussed the thermal excursions of different types of vials within different types of cryoboxes. The results are surprising. For example, samples can warm as quickly as 70°C/minute and a sample can warm from -180°C to -135°C (Tg) in less than 40s. A vial’s location and its surrounding vials have a huge effect on its warming rate.
And did you know that when using a cryobox with holes in the bottom, its samples will warm faster when placed from -180°C onto dry ice than when placed in an ambient environment? Quite counterintuitive, but likely due to increased convection from the sublimation of the dry ice.
Download Dr. Salvetti’s poster: “Bio-Samples Thermal Protection.”