Density Gradient Media
$200.00 - $600.00
All products have special prices for bulk purchase, please contact for more details if required.
Cat. No.: DGM-25 (for 25ml)
Cat. No.: DGM-100 (for 100ml)
Description
Density Gradient Media, also referred to as density gradient solution, density gradient medium, separation liquid or Centrifuge Density Buffer, is a separation medium built on the principle of density gradient centrifugation. It enables gentle, rapid and efficient isolation of diverse cell types, viruses and subcellular fractions within the density range of 1.0–1.3 g/mL.
This product is mainly composed of polyvinylpyrrolidone (PVP)-coated silica particles with a diameter of 15–30 nm, where free PVP only accounts for 1–2% of the total composition. It delivers outstanding physicochemical stability, non-toxicity, low viscosity, low osmotic pressure and excellent cellular biocompatibility. Due to the heterogeneous particle sizes of silica beads, they sediment at varying speeds during centrifugation and spontaneously form a continuous isotonic density gradient, which can separate most biological particles with a sedimentation coefficient above 60S.
Features
- Wide Range of Applications: This medium is applicable to the isolation of cells, subcellular particles, bacteria and viruses. It can also separate intact viable cells from damaged cells and cell debris.
- Broad Compatibility with Various Buffers & Tunable Density Range: Compatible with multiple buffer systems including PBS, HBSS, DMEM and RPMI-1640, it can be diluted to prepare density gradients ranging from 1.0 to 1.3 g/mL.
- Superior Grade with Rigorous Quality Control: Manufactured with high-grade raw materials and optimized formulas, this medium maintains consistent and stable performance.
- This sterile solution appears colorless to pale yellow, with the key features listed below:
- Generates isotonic gradients covering a density span of 1.0–1.3 g/mL;
- Non-toxic and chemically inert, with no adhesion to cell membranes;
- Allows precise adjustment of physiological ionic strength and pH value;
- Low viscosity for fast gradient formation;
- High stability; the stock solution tolerates repeated autoclaving.
Physical Parameters
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Storage
Store at 4 °C or room temperature for a shelf life of 2 years. When stored at −20 °C, the product remains stable for 6 months. After first opening, keep the medium at 4 °C at all times.
Precautions
- This density gradient medium maintains stable performance without interference within a pH range of 5.5–10.0. At pH values below 5.5, however, colloidal silica particles will gel (aggregate), disrupting system stability. Divalent cations (e.g., Ca²⁺, Mg²⁺) can also trigger gelation, and high temperatures will exacerbate this reaction. Avoid exposure to low-pH environments or high-salt buffers containing divalent cations during use.
- Saline- or sucrose-containing dilutions of the medium are prone to gelation or caramelization. For strict sterilization requirements, only autoclave undiluted stock medium (without added salt or sucrose) at 121 °C for 30 minutes. Sterilization via 0.22 μm filtration is not recommended.
- Minimize air exposure during autoclaving to prevent solid particle formation at the liquid-air interface. Narrow-mouth bottles are recommended to reduce the interfacial area. If particles form post-sterilization, remove them by 0.45 μm filtration or low-speed centrifugation at 500 × g for 5 minutes.
- If volume loss occurs after autoclaving, replenish with an equal volume of distilled water; the medium density will remain unchanged.
- If stored frozen at −20 °C, a density gradient will form upon thawing. Thoroughly mix the medium before use.
- Silica sediment often accumulates at the tube bottom or sidewalls after density gradient centrifugation. These precipitates become difficult to remove once dried. Rinse all labware with water immediately after use if necessary. Polycarbonate (PC) centrifuge tubes are strongly recommended.
- For research use only by qualified laboratory personnel. This product is not intended for clinical diagnosis or therapy, food or pharmaceutical manufacturing, or residential storage.
- Wear a lab coat and disposable nitrile gloves during handling for personal safety and protection.
Only for research and not intended for treatment of humans or animals
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