Traditional sperm cryopreservation for aquatic species heavily depends on expensive computer controlled programmable freezers, which are often unaffordable for resource-limited communities. In recent decades, open soured hardware has been developed for cryopreservation processing in aquatic species to assist global communities in establishing germplasm repositories. For example, open source 3-D printed hardware developed by the Aquatic Germplasm and Genetic Research Center (AGGRC, www.aggrc.com) can be shared by use of digital files around the world.
The lack of commercially available products for field-friendly cryopreservation solutions can cause a pervasive lack of standardization and reproducibility. To address this, the Shipping Dewar Position Cooling Device, also known as the “Cajun Ejector” was developed as a 3-D printed, affordable, open-source solution to use with large nitrogen vapor shipping dewars to process French straws at various cooling rates to meet the needs of users. Large nitrogen vapor shipping dewars are typically expensive and bulky, making them less than ideal for wide adoption by the community. To overcome this, the “Universal Cajun Ejector” was developed to be used with various sizes of shipping dewars, increasing accessibility and for global communities.
The Universal Cajun Ejector (Figure1) consists of five 3-D printed components and non-3-D printed part (i.e. a spring) The 3D-printed elements include the upright support, positioning rod, ejection cap, and dewar collar. To assemble the Universal Cajun Ejector, the positioning rod fits into the upright support, securely holding 22 French straws between the two pieces. The spring is placed around the positioning rod with the ejection cap screwed on to fasten the spring in place. This device is being tested for reproducing target ranges of cooling rates.
These efforts are standardizable through community efforts and improve the reproducibility of field-based cryopreservation. The development of open-source hardware can potentially revolutionize the community-level progress in establishment of germplasm repositories for aquatic species to support biomedical research, aquaculture, and conservation.