Membrane ultrafilter Vivafree™ 500

plasmafor serumfor protein solutions

Product overview
Vivafree™ 500 centrifugal ultrafiltration devices provide rapid separation of free drugs and hormones from plasma or serum for Therapeutic Drug Monitoring and clinical assays. Designed for 500 µl starting volumes and compatible with fixed-angle and swinging-bucket rotors that accept 1.5 ml / 2.2 ml conical tubes. Intended for in vitro diagnostic (IVD) use.

Applications

• Separation of free hormones (testosterone, insulin, cortisol).
• Sample preparation for therapeutic drug monitoring (phenytoin, valproic acid, antibiotics, immunosuppressants).
• Protein removal prior to mass spectrometry analyses.
• Preparation of samples for drug binding and pharmacokinetic studies.

Performance

• Vivafree™ 500 — MWCO 125,000 Da — Free Insulin: initial 500 µl → filtrate ~150 µl; 30 min; 37 °C; 2,000 x g.
• Vivafree™ 500 — MWCO 30,000 Da — Free Piperacillin: initial 500 µl → filtrate ~100 µl; 30 min; 25 °C; 2,500 x g.
• Vivafree™ 500 — MWCO 30,000 Da — Free Tazobactam: initial 500 µl → filtrate ~100 µl; 30 min; 25 °C; 2,500 x g.
• Vivafree™ 500 — MWCO 30,000 Da — Free Linezolid: initial 500 µl → filtrate ~90 µl; 20 min; 37 °C; 1,000 x g.
• Vivafree™ 500 — MWCO 30,000 Da — Free Fluconazole: initial 500 µl → filtrate ~90 µl; 20 min; 37 °C; 1,000 x g.

Note: Filtration times depend on sample volume and quality. Lipemic samples may require longer spin times. Filtration in swinging-bucket rotors is typically 2–3× slower than in fixed-angle rotors.

Technical Specifications (summary)

• Concentrator capacity: 0.5 ml (swinging bucket and fixed-angle rotor).
• Dimensions: total length 45 mm; width 12.4 mm; active membrane area 0.32 cm².
• Hold-up volume (membrane and support): <5 µl.
• Dead stop volume: fixed-angle rotor (40°) — 5 µl; swinging-bucket — no dead stop.
• Materials: body — polycarbonate; filtrate vessel & back spin vial — polypropylene; O-ring — silicone.
• Membranes available: Hydrosart® (125,000 MWCO) and Cellulose Triacetate (125,000 MWCO); additional MWCO variants available (e.g., 30,000 Da).
• Recommended centrifuge: rotors fitting 1.5 ml / 2.2 ml conical tubes; max speeds: up to 5,000 x g for 30,000 MWCO, up to 2,500 x g for 125,000 MWCO (refer to instrument specifications).

Features / Technical notes

• Starting sample volume: up to 500 µl (Vivafree™ 500).
• Typical filtrate yields: ~90–150 µl depending on analyte and conditions.
• Active membrane area: 0.32 cm²; hold-up volume <5 µl.
• Dead stop: 5 µl for 40° fixed-angle rotors; none for swinging-bucket rotors.
• Construction: polycarbonate body; polypropylene filtrate vessel and back spin vial; silicone O-ring.
• Membrane options and MWCO selection suited to assays for drugs and hormones.
• Optimized for fast separations with high recovery and reproducibility in clinical and research workflows.