Detection of the genomic DNA of pathogenic [alpha]-proteobacterium Ochrobactrum anthropi via magnetic DNA enrichment using pH responsive BSA@Fe.sub.3O.sub.4 nanoparticles prior to in-situ PCR and electrophoretic separation

Magnetite nanoparticles coated with bovine serum albumin (BSA@Fe.sub.3O.sub.4 MNPs) were used for efficient isolation and detection of genomic DNA from pathogen, Ochrobactrum anthropi. The pH tunable BSA-coated magnetic nanoparticles (BSA@Fe.sub.3O.sub.4) were synthesized by co-precipitation method and are shown to be capable of adsorbing almost 99 % of calf thymus DNA, from where it also can be efficiently desorbed by changing the pH of the suspension to 8. This finding enables efficient magnetic enrichment of DNA, followed by in-situ PCR of DNA. Over all, the detection limit of the method is 0.01 pg·mLâ¾.sup.1 for the genomic DNA of Ochrobactrum anthropi. The process does not require organic solvents or sophisticated equipment. Such an approach to fabricate and employ charge responsive Fe.sub.3O.sub.4@BSA magnetic nanoparticles for detection of pathogen has potential diagnostic and clinical applications.