Table 1. Comparison of the minimal concentrations required for vitrification using high-pressure cryocooling and flash cooling.

The concentrations for achieving ∼70% success rate are listed for high-pressure cryocooling. Data for flash cooling were obtained from McFerrin & Snell (2002 ▶) and Berejnov et al. (2006 ▶). Note samples in the present study were prepared in capillaries, while the references adopted Hampton Research CryoLoops (McFerrin & Snell, 2002 ▶) or MiTeGen MicroMounts (Berejnov et al., 2006 ▶).

Cryoprotectant†	High-pressure cryocooling	Flash cooling
PEG 200	15%(v/v)	35.7–37.5%(v/v)
PEG 400	10%(v/v)	>35%(v/v)
Glycerol	8%(v/v)	31.7–33.3%(v/v)

^†Sample volumes are ∼0.8 µl in this study and 0.5–1.0 µl in that of Berejnov et al. (2006 ▶), whereas sample volumes were not specified by McFerrin & Snell (2002 ▶).