Štěpánka Trachtová

Silica‐coated La0.75Sr0.25MnO3 nanoparticles for magnetically driven DNA isolation

Magnetic La(0.75)Sr(0.25)MnO(3) nanoparticles possessing an approximately 20-nm-thick silica shell (LSMO(0.25)@SiO(2) ) were characterised and tested for the isolation of PCR-ready bacterial DNA. The results presented here show that the nanoparticles do not interfere in PCR. DNA was apparently reversibly adsorbed on their silica shell from the aqueous phase system (16% PEG 6000-2 M NaCl). The method proposed was used for DNA isolation from complex food samples (dairy products and probiotic food supplements). The isolated DNA was compatible with PCR. The main advantages of the nanoparticles tested for routine use were their high colloidal stability allowing a more precise dosage and therefore high reproducibility of DNA isolation.

Magnetic Hydrophilic Poly(2-Hydroxyethyl Methacrylate-co-Glycidyl Methacrylate) Microspheres for DNA Isolation from Faeces

Magnetic non-porous hydrophilic poly(2-hydroxyethyl methacrylate-co-glycidyl methacrylate)-P(HEMA-co-GMA) microspheres containing carboxyl groups were used for DNA isolation from mouse faeces spiked by a probiotic Lactobacillus gasseri K7 strain. The quality of isolated DNA and the presence of target DNA were verified by PCR and real time PCR using primers specific for Lactobacillus genus or primers targeting gassericin A gene of the Lactobacillus gasseri K7 strain. For comparison, two other DNA extraction procedures were used. It was shown that DNA extracted by carboxyl-coated P(HEMA-co-GMA) microspheres were sufficient for the amplification of target DNA using PCR and real-time PCR.