Project Summary

CryoKit v1.0 (Fig. 1) is a type of Positional Cooling Platform Devices (PCPD) that can be 3-D printed to produce standard cooling rates with low cost (< $10). Multiple configurations of the raft and height above the liquid nitrogen surface were used to produce a range of cooling rates typically used for fish sperm (i.e., from 4 °C/min to 40 °C/min) (Fig. 2). This was the earliest version of the concept of a 3-D printed PCPD. This device can be assembled within several min with 3-D printed parts (Fig. 3). Several new versions has been developed since the feasibility of CryoKit v1.0 was recognized.

Figure 1. Illustration of loading CryoKit v2.0 with cryopreservation vials (top left) and straws (top right) to be cooled with liquid nitrogen vapor in a standard Styrofoam box (bottom images)
Figure 2. Representation of cooling curves for different container configurations. The freezing device was designed to provide a range of reproducible cooling rates for four containers: 0.5-ml French straws, 0.25-ml French straws, 2-ml Cryovial, and 0.5-ml Nunc Bank-it tubes. A range of cooling rates was produced by various combinations of rafts area) and column height (40 mm, 50 mm, or none). Such cooling curves could be used for reference among different users.
Figure 3. Components of CryoKit v1.0. A: the appearance of CryoKit v2.0 and inside view; B: hollow boat and square boat; C: components of rack (holding surfaces and supporting bars); D: components of lifter (bottom, lifter bars, and handler) and measurement stick.