Complete Guide to Oocyte Vitrification

#oocyte #vitrification

If you manage an IVF laboratory in the UK, oocyte vitrification protocol decisions directly impact your post-thaw survival rates, HFEA compliance, and ultimately patient outcomes.

Here's a technical breakdown of what matters most:

The Core Science
Vitrification achieves cooling rates of 15,000–30,000°C per minute — fast enough to prevent ice crystal nucleation entirely. The cell contents solidify into an amorphous glass-like state rather than forming crystalline ice that ruptures organelles and membranes.

Closed vs Open Systems — The UK Compliance Issue
Open vitrification systems achieve marginally faster cooling rates but expose samples to direct liquid nitrogen contact. Under HFEA infection control guidelines, closed systems are increasingly required for UK-licensed clinics — particularly for patients with blood-borne infections.

CBS High Security Straws are the dominant closed system in UK IVF labs for good reason — they achieve cooling rates comparable to open systems while maintaining complete biological containment.

Storage Temperature Consistency
Post-vitrification, maintaining consistent -196°C storage is non-negotiable. Any temperature excursion — even briefly above -130°C (the glass transition temperature) — risks recrystallisation and sample loss.

Equipment Stack for UK IVF Labs