Detection of Mycobacterium Tuberculosis by Magnetic Nanoparticle Capture-Polymerase Chain Reaction

Abstract

This work aimed to study the experiment of Mycobacterium tuberculosis (MTB) detection via magnetic nanoparticle (MNP) capture combined with polymerase chain reaction (PCR) technology. Thirty sputum samples were collected, MTB was isolated and cultured, and DNA templates were prepared. Fe3O4-polyethylene imide (PEI) MNPs were prepared, and PCR was adopted to test the 30 samples. Within the range of 0–600 °C, as the temperature rose, the quality of Fe3O4-PEI MNPs was gradually reduced. MNPs were positively charged when the pH value was 2–8. The highest capture rate of MTB with OD500 = 0.4 was 71%. The highest capture rate of MTB with OD500 = 0.6 was 58%. The highest capture rate of MTB with OD500 = 0.8 was 26%. When the temperature was heated to 900 ˚C, the thermal weight loss of MTB was about 85% if MNP wasn’t added. The thermal weight loss of MNP-captured MTB was about 45%, while that of uncaptured MTB was about 71%. In summary, polyethyleneimine could enhance the adsorption of MNP to MTB, and the capture rate gradually increased over time. The lipid of the cell wall of MTB was involved in the interaction between MTB and MNP.