Differential scanning calorimetry (DSC) was employed to investigate the vitrification and annealing behaviors of the most commonly used plant vitrification solutions (PVS). These solutions are employed to protect plant tissues toward ice formation and freeze injury, and help to the vitrification of these tissues, by globally reducing the intracellular fluids mobility. Glass transition temperatures (T-G) and heat capacity increments (Delta Cp) were determined for five solutions PVS1, PVS2, PVS2 mod, PVS3 and PVS3 mod, with different composition, and a range of cooling and warming rates was employed. Glass transitions showed clear and consistent temperature differences within vitrification solutions, which could be related to composition and water content. Roughly, two sets of T-G values were obtained, those for PVS1 and PVS2, at -112 degrees C and -114 degrees C, respectively, and those for PVS3, at-90 degrees C. The observed T-G and Delta Cp, unexpectedly, did not significantly change within a wide range of cooling rates (from 5 degrees C min(-1) to liquid nitrogen quenching) and warming rates (from 5 to 20 degrees C). Garlic shoot tips cryopreserved after the droplet method produced a similar result to that of the vitrification solutions employed. After quench cooling to temperatures below T-G, repeated excursions to higher temperatures were made and the cooling and warming T-G were recorded. These treatments had little or no effect over the PVS solutions T-G, which remained practically constant. A direct practical consequence is that the plant vitrification solutions glass transition temperature does not significantly change with cryopreservation methods based on either direct plunging of samples into liquid nitrogen or employing closed cryovials. (C) 2014 Elsevier B.V. All rights reserved.