Preparation of silica particles
AssigneeQiagen GmbH
InventorRoland Fabis
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Abstract
The present invention provides a cost-efficient method for producing particles having a SiO2 containing surface wherein said method comprises a) providing an aqueous reaction composition comprising i) core particles, ii) an added base, iii) a silicate salt, and iv) a pH modulator wherein the pH value of the reaction composition is above the gelation pH value; b) agitating said reaction composition, wherein the pH modulator decreases the pH value of the reaction composition over time and wherein due to said decrease of the pH value of the reaction composition SiO2 is deposited onto the core particles, whereby particles are formed which have a diameter of 30 μm or less; and c) obtaining the particles. Furthermore, silica particles having high nucleic acid binding properties are provided.
Claims30
A method for producing particles having a SiO2 containing surface comprising:
- a) providing an aqueous reaction composition comprising
- i) core particles,
- ii) an added base,
- iii) a silicate salt, and
- iv) a pH modulator
- wherein the pH value of the reaction composition is above the gelation pH value of the silica salt;
- b) agitating said reaction composition, wherein the pH modulator is an organic compound that reacts in the alkaline milieu of the reaction composition, thereby decreasing the pH value of the reaction composition over time and wherein due to said decrease of the pH value of the reaction composition, SiO2 is deposited onto the core particles, whereby particles are formed which have a diameter of 30 μm or less;
- and
- c) obtaining the particles.
Porous silica particles having a size of 30 μm or less;
- and formed by agglomerated SiO2 coated core particles, wherein the core particles are essentially encapsulated by the SiO2 coating and wherein the silica particles have a composition regarding the comprised SiO2 and core particles that is 15 to 75% (by weight) core particles and 25% to 85% (by weight) SiO2, and wherein the silica particles are capable of binding at least 12.5 μg nucleic acid molecules per mg particles.
Dependencies are inferred from the claim text.