Protocol of each cooling procedure.

*

1/4 ml sample straw was covered with a 1/2 ml straw, a 7 mm OD ×90 mm glass tube, and a 10 mm OD ×90 mm glass tube.

†

The Cryotop was covered with the Cryotop-cap-straw and a 7 mm OD ×90 mm glass tube.

‡

The straw or Cryotop were placed horizontally on a Styrofoam disk (14 cm diameter, 1.5 cm thick) floated on the surface of LN₂ in a 41 Dewar flask for >5 min before being immersed in LN₂.

§

The cooling rates were determined from 20 to −120°C. N = 5.

¶

The cooling rates were determined in [14].