Cryopreservation Cost & Break-Even Calculator

Cryopreservation Cost Basics

Every line in your colony costs money every month you keep it alive. Cryopreservation lets you trade *recurring* cost (per-diem, husbandry time, cage space) for an *upfront* cost (the cryo procedure) plus an optional *recovery* cost when you actually need the line back.

• live_total = lines $\times$ annual_maint $\times$ years
• cryo_total = lines $\times$ cryo_cost + lines_to_recover $\times$ recovery_cost
• break_even_years = cryo_cost / annual_maint (per line, ignoring recovery)

Below break-even, live is cheaper. Above break-even, cryo is cheaper — *unless* you recover most of what you froze.

Cage space is often the binding constraint, not dollars. A cryo bank takes one freezer slot per line; a live colony takes 1-3 cages per line. If your facility is at capacity, cryo is the only way to add new lines without cutting old ones. The break-even math may not even matter when the rack is full.

Embryo vs Sperm Cryopreservation

Freeze 2-cell or 8-cell embryos. Recovery: thaw → embryo transfer to pseudopregnant recipient → full litter. High recovery rate (>80% in well-run cores). More expensive per line (~$1,800).

Freeze epididymal sperm from a few males. Recovery: IVF on fresh oocytes → embryo transfer. Cheaper per line (~$800), but recovery is harder, more variable, and more expensive ($2,000+). Sperm cryo is best for *archival* (we probably will not use this) and for males of inbred lines that breed reliably.

Embryo cryo your top 10-20% of lines (the ones you expect to recover within 2-5 years). Sperm cryo the long tail (lines you may never need but cannot ethically euthanize without an archival copy). Live-maintain only the active workhorses.