When is a controlled rate cryogenic freezer the wrong choice for an IVF laboratory and what should replace it?
The controlled rate freezer became the default cryopreservation tool in IVF laboratories during the 1980s and 1990s, when slow-freeze protocols were the only reliable method for embryo cryopreservation. Its role has narrowed considerably since vitrification became the dominant technique for oocytes and cleavage-stage embryos in the majority of UK clinics. A controlled rate cryogenic freezer is still the correct choice for sperm cryopreservation, blastocyst banking where slow-freeze protocols are specified, ovarian tissue preservation, and biobanking applications requiring a documented programmable cooling curve for regulatory purposes.
For oocyte and day 2 to day 3 embryo cryopreservation, vitrification consistently outperforms slow-freeze in published survival and clinical pregnancy rate data, and the equipment cost is lower because vitrification requires only the consumable carrier and a dewar rather than a programmable freezing unit. The question laboratories should ask before investing in a controlled rate cryogenic freezer is not whether the technology works, but whether their specific protocol mix justifies the capital cost and service commitment. Cryolab supplies the CBS DigitCool controlled rate freezer for applications where a programmable cooling curve is genuinely required, alongside the full CBS High Security vitrification kit range for laboratories where vitrification is the primary technique. Contact us to discuss which approach suits your protocol and cycle volume.
