|Year : 2020 | Volume
| Issue : 4 | Page : 140-143
A study on a virtual simulation experiment with DNA in a biological evidence technology course during the COVID-19 pandemic
Zhenjun Jia1, Gao Chunfang1, Dai Peng1, Liu Zhuo1, Qian Zunlei1, Yao Weixuan2
1 The School of Crime Scene Investigation, People's Public Security University of China, Beijing, China
2 Department of Criminal Science and Technology, Key Laboratory of Drug Prevention and Control Technology of Zhejiang Province, Zhejiang Police College, Hangzhou, Zhejiang, China
|Date of Submission||17-Oct-2020|
|Date of Acceptance||07-Dec-2020|
|Date of Web Publication||05-Jan-2021|
The School of Crime Scene Investigation, People's Public Security University of China, Beijing 10038
Source of Support: None, Conflict of Interest: None
Biological evidence technology plays an important role in the field of crime scene investigation. DNA technology is known as one of the important ways to make a breakthrough in the resolution of a criminal case. Nonetheless, there are some problems in on-site experiment-based teaching during the COVID-2019 pandemic, which limits the students' incentives to acquire knowledge about DNA. Under these conditions, the goals and requirements of the Biological Evidence Technology course cannot be achieved. A virtual simulation experiment can solve these problems online. The students can gain a deeper understanding of the process and method of human DNA extraction and identification, and thus, the impact of experiment-based teaching improves. In this paper, we discuss the contents of DNA experiments, specifications of the simulation system, system requirements, the implementation process, and other parameters of the design. We investigated the early teaching effect. A virtual simulation experiment with DNA can overcome the limitations of devices (and other equipment) and spatial and temporal limitations during the COVID-2019 pandemic. Students can participate in the whole process of experiment-based teaching. Teaching mode “Internet + laboratory” increases the open access and sharing of experiment-based teaching resources.
Keywords: Biological evidence technology, COVID-19, DNA, virtual simulation
|How to cite this article:|
Jia Z, Chunfang G, Peng D, Zhuo L, Zunlei Q, Weixuan Y. A study on a virtual simulation experiment with DNA in a biological evidence technology course during the COVID-19 pandemic. J Forensic Sci Med 2020;6:140-3
|How to cite this URL:|
Jia Z, Chunfang G, Peng D, Zhuo L, Zunlei Q, Weixuan Y. A study on a virtual simulation experiment with DNA in a biological evidence technology course during the COVID-19 pandemic. J Forensic Sci Med [serial online] 2020 [cited 2021 Jan 22];6:140-3. Available from: https://www.jfsmonline.com/text.asp?2020/6/4/135/306181
| Introduction|| |
Biological evidence technology plays an important role in criminal investigations, and DNA identification is regarded as one of the newer tools for solving crimes.,,, Conventionally, training in DNA testing and identification skills requires the use of a DNA laboratory, but in the past, field teaching of DNA experiments has often encountered the following problems: (1) Complicated procedures, tedious steps, and long experimental cycles necessitate additional time beyond the required hours of classroom instruction to complete the experiment-based teaching. (2) There are toxic and hazardous reagents, major safety hazards related to aqueous solutions and electricity, and a difficulty with protection from chemical hazards.(3) Some institutions do not have DNA labs or have laboratories (designed according to testing standards) that are too small to accommodate the teaching of a normal-size class. (4) Laboratory supplies are too expensive, which limits the range of students that can be taught. To some extent, these problems affect experiment-based teaching of biological evidence technology and the cultivation of students' innovation ability in practice. In particular, during the current COVID-19 pandemic, the inability to provide field teaching of DNA experiments limited students' enthusiasm for theoretical knowledge about DNA, and hence, the requirements for training in biological evidence testing and identification skills were not met.
Virtual simulation technology converts experiments–that involve highly toxic reagents or are difficult, time-consuming, expensive, or hard to implement in a traditional experiment-into virtual experiments, thereby allowing to “shorten long-duration experiments, miniature large-scale experiments, visualize microscopic experiments, improve the safety of dangerous experiments, enhance proficiency in complex experiments, and reproduce experiments that are hard to repeat.”,, Virtual simulation experiments with DNA extraction, amplification, and typing techniques for on-site biological-evidence samples can solve problems that arise in the field teaching of DNA experiments. Especially during the pandemic, experiment-based teaching can be implemented remotely and effectively, thereby allowing students to have a clear understanding of the process of human DNA extraction and testing, to gain a deeper insight into the DNA testing methods in biological evidence technology, and to truly apply the textbook knowledge to practice.
| The Design of a Virtual Simulation Experiment with DNA|| |
The design of content and a key technique
The DNA virtual simulation experiment system consists of four parts: DNA extraction, DNA quantification, polymerase chain reaction amplification, and electrophoretic typing.
The software is based on unity three-dimensional (3D) and developed in C# in Visual Studio. Simulation models (including models and textures) are created by means of Maya and 3D Max, and 3D animations are generated through skeletal animations, keyframes, and sequential frame animations.
System requirements for the server are as follows: a 4-core CPU, 32 GB of RAM, 500 GB of disk space, 2 GB of video memory, a GPU (no model requirement), operating system Windows Server 2018 R2, and a MySQL database. [Figure 1] shows parts of the operational interface.
|Figure 1: Some operational interfaces of a virtual simulation experiment with DNA|
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System specifications and functions
Each component is available in a multiuser collaborative installation version. Multiple workstations can be set up and are connected via LAN. The system has a student workstation and a teacher's inspection-and-guidance workstation. Students access the system through their student accounts to practice simulations, learn to navigate through the DNA experiments in demo mode, and practice and evaluate their performance in real time in operation mode. Teachers access the system through teacher accounts to see, for example, how long students have been working with the software, their proficiency level, and their grades. Moreover, the system contains an intelligent operation guidance and evaluation environment that can generate and export or print out transcripts. The system has four major functions, namely, real-time scoring, a knowledge point system, tips on avoiding errors and pitfalls, and visualization of experimental details.
The process of implementation of the DNA virtual simulation system
The implementation flow of the DNA virtual simulation system is shown in [Figure 2]. The system includes a demo mode and operation mode. In demo mode, an experiment is demonstrated step by step using 3D animation, and previous and next steps can be controlled. Any step can be selected by accessing the progress bar. Experiments can be conducted freely in operation mode, with the ability to browse independently within a 3D scene and to execute steps through menus.
| Evaluation of the Virtual Simulation Experiment with DNA|| |
During the pandemic, our school launched the teaching of virtual simulation experiments with DNA. Ten students who had experience with the DNA virtual simulation system were selected for a questionnaire survey, which was conducted using the electronic questionnaire from Sojump (China). The results were as follows.
Response options about the overall experience with the DNA virtual simulation software ranged from unsatisfactory (0) to very satisfactory (10). Forty percent of the students rated their experience as a 10, 30% as 9, 20% as 8, and 10% as 7, with a mean score of 9 (standard deviation: 1.05).
Response options regarding the usefulness of virtual simulation experiments with DNA for helping to understand the theory about biological evidence amid the current COVID-19 outbreak ranged from not useful (0) to very useful (10). Seventy percent of the students rated the usefulness as a 10, and 10% scored it at 9, 8, and 7, respectively, with a mean score of 9.4 (standard deviation: 1.07).
Regarding the advantages of virtual simulation experiments over traditional on-site experiments during the pandemic, 90% of the students were found to believe that virtual simulation experiments with DNA break down the distance barrier and allow for remote teaching of experiments. One hundred percent of the students opined that virtual simulation experiments with DNA transcend time constraints and may be learned at any time. One hundred percent of the students noted that virtual simulation experiments with DNA allow an entire class and additional classes to conduct experiments together, overcoming spatial limitations. One hundred percent of the students thought that virtual simulation experiments with DNA are free from chemical reagents and that the experiments are nontoxic and harmless. One hundred percent of students felt that virtual simulation experiments with DNA can be repeatedly practiced and reviewed as needed. Ninety percent of the students argued that DNA virtual simulation experiments can significantly reduce experiment costs as compared to on-site DNA experiments.
Response options as to whether virtual simulation experiments can completely replace on-site experiments ranged from absolutely impossible (0) to completely possible (10). Ten percent of the students chose option 4, 20% option 6, 50% option 7, and 20% 8, with a mean score of 6.7 (standard deviation: 1.16).
| Conclusions|| |
Achieving full student participation in experiment-based teaching and learning
With the virtual simulation system, the “limited participation” of students in DNA experiments is transformed into a “hands-on process” for all students, enabling 100% “full-procedure” participation of students. According to the questionnaires, students believe that virtual simulation experiments with DNA can overcome the limitations on time, space, and instrumentation.
Improving the effectiveness of experiment-based teaching through a virtual-real combination
The DNA extraction and identification experiments with on-site biological evidence are molecular experiments, and the actual processes cannot be observed directly. The success of the experiments can be verified only after amplification and electrophoresis assays are completed. Through virtual simulation experiments, abstract concepts associated with the experiment, for example, changes in DNA, proteins, or other submicroscopic entities, are presented in the form of an Adobe Flash animation or short films, vividly and realistically showing the molecular processes involved in the experiments, increasing fun, enhancing the students' mastery of knowledge and skills, and improving the effectiveness of experiment-based teaching.
Reducing the hazards of experiments and improving the safety of experiment-based teaching
Chloroform, saturated phenol, ethidium bromide, and other reagents in DNA extraction and identification experiments with on-site biological evidence are toxic and some of them are carcinogenic to humans. Virtual-simulation-based teaching can greatly reduce the toxicity and other hazards of experiments and should significantly improve the safety of experiment-based teaching. One hundred percent of the students were found to think that virtual simulation experiments with DNA are free from chemical reagents and that the experiments are nontoxic and harmless.
Reducing the investment in laboratory construction and the cost of experiment-based teaching
Laboratory equipment and supplies are all virtualized. The reform involving experiment-based teaching of DNA basics and techniques, the adjustment of experimental items, and the optimization of DNA experiment-based programs can be independent of the performance of experimental equipment. Virtual simulation can effectively solve the problems of traditional experiment platforms, for example, the long construction cycle, sizeable investment, and inadequate upkeep and supplies, and can ensure normal teaching.
Promoting open sharing of experiment-based–teaching resources
The DNA virtual simulation experiment-based teaching system offers the “Internet + Lab” teaching mode and is open to all students who take courses. On the unified portal, on-campus students can access applicable experimentation platforms depending on the courses they choose to study. By mastering experimentation skills under virtual simulation conditions, students can understand and master the principles and practical operational knowledge of DNA extraction and identification within a short period. Experiment-based teaching for a wide range of students is no longer limited by the location of a laboratory, thereby demolishing the barriers of traditional DNA experiment-based teaching.
This article was originally released in Chinese language in the Chinese Journal of Forensic Medicine. The publication has been approved by the editorial office of Chinese Journal of Forensic Medicine.
Financial support and sponsorship
The Teaching Reform Project of People's Public Security University of China (2019JY34); the Research Project on Studying and Implementing the Gist of the Fourth Plenary Session of the 19th CPC Central Committee (2020SZQH17); a Project Funded by Basic Scientific Research Expenses (2019JKF217); the Initiative Design Project of Hangzhou Agricultural and Social Development Research (20190101A08); the Key Laboratory Project of Drug Prevention and Control Technology of Zhejiang Province (2018YFC0807201).
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]