Conditions of polymerase chain reaction amplification by magnetic enrichment and nanoscale detection sensitivity

In this research, we reported a method of polymerase chain reaction (PCR) amplification by means of magnetic enrichment. First, after denaturation, the target sequence was combined with biotin-modified specific primer through hybridization and enriched at the surface of gamma-Fe2O3 by biotin-avidin special interaction. Then single target sequence was gained through denaturation, and general PCR amplification was performed. The experiment conditions such as the hybridization temperature between target sequence and biotin-modified specific primer, and the dosage of magnetic nanoparticles gamma-Fe2O3 were optimized. Finally, the sensitivity of the method was checked. The lowest concentration of target sequence was detected as low as 5 x 10(-7) ng/mL. This simple method could provide a quick and early diagnosis of malignant infectious diseases such as SARS, avian flu and swine flu etc., that occur occasionally nowadays.