Journal of Forensic Medicine ›› 2023, Vol. 39 ›› Issue (1): 45-49.DOI: 10.12116/j.issn.1004-5619.2022.520202

• Techniques and Applications • Previous Articles     Next Articles

Comparative of Forensic DNA Identification Using Cell Lysis Method and Magnetic Beads Method

Jia-jun SHI1(), Dan WU2, Tie-zhu LIU3, Si-jing HAO1, Bi-cheng MENG1, Shi-lin LI4, Ya-nan LIU1()   

  1. 1.Key Laboratory of Forensic Evidence and Science Technology, Ministry of Public Security, Shanghai Key Laboratory of Crime Scene Evidence, Shanghai Research Institute of Criminal Science and Technology, Shanghai 200083, China
    2.Shanghai Public Security College, Shanghai 200137, China
    3.Institute of Criminal Science and Technology, Putuo Branch of Shanghai Public Security Bureau, Shanghai 200333, China
    4.Department of Anthropology and Human Genetics, School of Life Sciences, Fudan University, Shanghai 200438, China
  • Received:2022-02-24 Online:2023-02-25 Published:2023-02-28
  • Contact: Ya-nan LIU

Abstract:

Objective To compare the effects of cell lysis method and magnetic beads method in forensic DNA identification and to explore these two methods in forensic DNA identification. Methods The genome DNA of THP-1 cells in different quantities was extracted by the cell lysis method and magnetic beads method, and the DNA content was quantified by real-time quantitative PCR. The cell lysis method and magnetic beads method were used to type the STR of human blood with different dilution ratios. Results When the numbers of THP-1 cell were 100, 400 and 800, the DNA content extracted by cell lysis method were (1.219±0.334), (5.081±0.335), (9.332±0.318) ng, respectively; and the DNA content extracted by magnetic beads method were (1.020±0.281), (3.634±0.482), (7.896±0.759) ng, respectively. When the numbers of THP-1 cells were 400 and 800, the DNA content extracted by the cell lysis method was higher than that by the magnetic beads method. The sensitivity of cell lysis method and magnetic beads method was similar in STR typing of human blood at different dilution ratios. Complete STR typing could be obtained at 100, 300 and 500-fold dilutions of blood samples, but could not be detected at 700-fold dilution. STR typing of undiluted human blood could not be detected by cell lysis method. Conclusion The cell lysis method is easy to operate and can retain template DNA to the maximum extend. It is expected to be suitable for trace blood evidence tests.

Key words: forensic genetics, cell lysis method, magnetic beads method, short tandem repeat (STR), THP-1 cells

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