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# c12) United States Patent Fabis 

# (54) PREPARATION OF SILICA PARTICLES 

(71) Applicant: QIAGEN GmbH, Hilden (DE) 

(72) Inventor: Roland Fabis, Leverkusen (DE) 

(73) Assignee: QIAGEN GmbH, Hilden (DE) 

( *) Notice: Subject to any disclaimer, the term ofthis patent is extended or adjusted under 35 U.S.C. 154(b) by 142 days. 

(21) Appl. No.: 14/650,645 

(22) PCT Filed: Dec. 11, 2013 

(86) PCT No.: PCT/EP2013/076150 § 371 (c)(l), (2) Date: Jun. 9, 2015 

(87) PCT Pub. No.: WO2014/090838 PCT Pub. Date: Jun. 19, 2014 

## (65) Prior Publication Data 

US 2015/0307870 Al Oct. 29, 2015 

## (30) Foreign Application Priority Data 

Dec. 11, 2012 (EP) ..................................... 12196503 

(51) Int. Cl. 

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(52) U.S. Cl. CPC ......... C12N 1511013 (2013.01); C0lG 49106 (2013.01); C0lG 49108 (2013.01); 

( 58) Field of Classification Search CPC ........ C04B 35/62807; C04B 35/62849; C04B 2235/3272; C04B 2235/5436; C04B 2235/5445; C0lP 2006/42; C09C 1/24 

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# (IO) Patent No.: US 9,938,520 B2 

# Apr. 10, 2018 (45) Date of Patent: 

## (56) References Cited 

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Solberg & Landry, Adsorption of DNA into Mesoporous silica, J. Phys. Chem. B 2006, ll0, 15261-15268.* 

Primary Examiner - Hoa T Le 

(74) Attorney, Agent, or Firm - Seed IP Law Group LLP 

## (57) ABSTRACT 

The present invention provides a cost-efficient method for producing particles having a SiO$_{2 }$ 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 composi› tion, 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 SiO$_{2 }$ 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. 

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US00993 8520B2 

## U.S. PATENT DOCUMENTS 

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## FOREIGN PATENT DOCUMENTS 

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## OTHER PUBLICATIONS 

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35 Claims, 4 Drawing Sheets 

