The new vitrification and warming protocols: when rapid is not really rapid.

Area of Science:

• Cryobiology
• Reproductive Medicine
• Biotechnology

Background:

• Novel vitrification and warming protocols aim to reduce cryoprotectant exposure time.
• Current terminology often misrepresents these protocols as 'rapid' or 'ultra-fast.'

Purpose of the Study:

• To clarify the terminology used for new cryopreservation protocols.
• To distinguish between protocols that shorten solution times and those that increase thermal rates.

Main Methods:

• Analysis of current terminology in cryopreservation literature.
• Comparison of newly developed protocols with historical definitions of 'rapid' and 'ultra-fast' rates.

Main Results:

• New protocols often reduce time in cryoprotectant solutions (CPA) or omit steps, rather than increasing cooling/warming rates.
• The terms 'rapid' and 'ultra-fast' are misleading when applied to protocols that do not alter thermal kinetics.

Conclusions:

• Protocols reducing CPA exposure time should be termed 'shortened protocols,' not 'rapid.'
• Accurate terminology is essential for clear communication, data interpretation, and clinical application in cryopreservation.
• Only protocols increasing physical cooling or warming rates should be labeled 'rapid' or 'ultra-fast.'