Sterile: Yes
Universal Virus Concentration Solution (3×) is a simple, rapid and high-efficiency reagent for concentrating a variety of common recombinant viruses. Traditional virus purification relies on ultracentrifugation, which is time-consuming, requires sophisticated equipment and only processes a limited volume of viral supernatant. This concentration reagent can be directly added to virus-containing supernatant to precipitate virions. The viral titer can be effectively elevated via simple centrifugation and resuspension steps. The maximum virus recovery rate reaches approximately 90%, and the viral titer can be concentrated 10–100 fold.
This product is applicable for concentrating virions produced in laboratory packaging systems, including Lentivirus, Retrovirus, Adeno-associated virus (AAV), Adenovirus and Baculovirus.
Application Protocol
1.After virus packaging, collect virus-containing cell supernatant. Centrifuge at 3500×g for 10 min at 4 °C to fully pellet cell debris, then carefully transfer the supernatant for subsequent concentration. Alternatively, filter the viral supernatant through a 0.45 μm syringe filter to remove cell debris.
Note: Only polyethersulfone (PES) membrane syringe filters are recommended for filtering viral supernatant. Membranes made of other materials such as nitrocellulose (NC) may adsorb viruses.
2.Take out the 3× virus concentration solution stored at 4 °C, and mix it with viral supernatant at a volume ratio of 1 part 3× concentration solution to 2 parts viral supernatant. Invert the tube thoroughly to homogenize, then incubate the mixture at 4 °C for 6–8 hours. The solution usually turns turbid after sufficient incubation at 4 °C. Extended incubation (e.g., overnight at 4 °C) helps improve virus recovery, but the incubation duration must not exceed 24 h.
Notes:
(1) The 3× virus concentration solution is highly viscous. Aspirate and dispense slowly, and ensure complete homogenization between the concentration solution and viral supernatant to guarantee satisfactory virus recovery.
(2) The entire concentration process must be maintained at 4 °C. Longer incubation time is recommended for samples with a volume exceeding 100 mL.
3.Centrifuge the mixture at 7000×g for 0.5–1 h at 4 °C. A white pellet is usually visible at the bottom of the centrifuge tube (occasionally the pellet may be invisible). Carefully aspirate and discard the supernatant without touching the pellet, and avoid vigorous shaking of the tube.
4.Centrifuge again at 7000×g for 1 min at 4 °C, then thoroughly aspirate residual liquid without disturbing the pellet.
5.Add virus resuspension buffer equivalent to 1–10% of the original viral supernatant volume to cover the pellet, let it stand for 10 min, then gently pipette up and down 20–30 times to resuspend the viral pellet. Avoid generating air bubbles during pipetting, as harsh pipetting may inactivate viruses.
Notes:
(1) If no distinct white pellet is observed, gently pipette the region where the pellet is expected to form.
(2) The amount of white precipitate does not represent viral yield. Apart from virions, the pellet contains serum proteins, trace cell debris and genomic DNA.
(3) Multiple resuspension buffers are optional according to downstream experiments, including serum-containing medium, serum-free medium, PBS and D-Hank’s solution.
6.Centrifuge at 12,000×g for 3–5 min at 4 °C. The supernatant harvested after centrifugation is concentrated virus stock. Aliquot as required for subsequent assays and store at −80 °C for long-term preservation. The pellet generated in this step contains serum proteins, trace cell debris and genomic DNA.
Precautions
1.To prevent virus inactivation, avoid repeated freeze-thaw cycles for both pre-concentration viral supernatant and concentrated virus stock.
2.Serum in cell culture medium facilitates viral precipitation and concentration. If virus packaging is performed in serum-free or low-serum medium, or if viruses need to be concentrated from low-protein solutions, add sterile BSA to a final concentration of 3% during concentration to significantly improve performance.
3.All virus-related manipulations must be carried out in a biosafety laboratory. All consumables exposed to viral liquid shall be properly treated following biosafety protocols to prevent contamination.
4.This product is for research use only by professional personnel. It shall not be used for clinical diagnosis or treatment, food or pharmaceutical production, nor stored in residential premises.
5.Wear a lab coat and disposable gloves throughout all operations for personal safety and health protection.
