Thaw frozen Fetal Bovine Serum (FBS) overnight at 2℃ to 8℃ then transfer it to a 37℃ water bath or at room temperature and swirl gently every 10–15 minutes until fully melted. Avoid rapid heating(>37℃) microwaves, or repeat freeze-thaw cycles, which denature vital growth factors and cause heavy protein precipitation. It is essential to shake it evenly at regular intervals during the thawing process.
- Why Temperature Control Matters
-Prevents Cryo-Precipitation: As ice melts, dense salts and proteins sink to the bottom. Without periodic swirling, high local salt concentrations cause proteins to aggregate into insoluble flakes.
-Protects Heat-Sensitive Factors: Temperatures above 37℃ denature essential signaling proteins (e.g., IGF-1, FGF), reducing cell proliferation.
- 4-Step Standard Thawing Protocol
1. Cold Refrigeration (Step-Down):12–24 Hours。
Move frozen FBS from -20℃ to a 2℃ to 8℃ refrigerator overnight to prevent thermal shock.
2. 37°C Water Bath:30–60 Minutes。
Place the bottle in a 37℃ water bath (keep the cap above water to avoid contamination) or at room temperature .
3. Intermittent Swirling:Every 10–15 Mins。
Gently invert the bottle periodically to disperse the salt/protein gradient and prevent precipitation.
4. Immediate Aliquoting:Aseptic Hood。
Remove immediately once thawed, wipe with 70% ethanol, and aliquot into single-use tubes to avoid repeat freeze-thawing.
- Frequently Asked Questions
Q: What if I see flakes/precipitate after thawing?
A: Minor precipitation is normal (insoluble fibrin/lipoproteins) and does not impair cell growth. Clarify by brief centrifugation (400×g, 5 min) or 0.2μm PES filtration.
Q: How long does liquid FBS last at 2 ℃ to 8 ℃ ?
A: Fully thawed liquid FBS remains stable at 2 ℃ to 8 ℃ less than one month. Keep long-term stocks frozen at -5℃ to -20℃ .
Visit us today at www.qymbiomaterial.com to explore our full range of bio-materials.
QYM-Your Trusted Partner for High-quality bio-materials and keep your brand trustworthy with stable, cost-effective bio-materials.
DM us for more technical data and samples.