We have interacted with nearly 20 teams this year. We helped each other in the CRISPR technology and protein engineering design. We also presented our project at the national conference, and ran our own iGEM public account on the WeChat and Bilibili platforms in the summer!

CRISPR CONFERENCE

On September 12, 2021, we were glad to be invited by the iGEM Tianjing 2021 to participate in the CRISPR conference with other 11 teams. Before the start of the meeting, the leaders of all teams drew lots to determine the partners of cooperation. Our NEFU team worked with the LZU team to solve their problems, while the ZJUT team helped us get through our current bottlenecks.

In the project of the LZU_China team, they planned to use a lentiviral vector to express the RfxCas13d gene and sgRNAs, which was used to target the hACE2 mRNA in a HEK293T/hACE2 stable cell line. Their problem was to choose either 30nt or 36nt Cas13d direct repeats when multiple pre-sgRNAs were expressed by a lentiviral vector. Through the discussion, we suggested that the length of direct repeats should not be too long, better within 30nt. Based on our exploration of literature, we indicated that different laboratories may use different lengths of the direct repeats to obtain their own results, and they would have to test under their experimental conditions.

In the course of our project, the major difficulty encountered by us was that the purified recombinant ¬Cas9 protein was not efficient in cleaving dsDNA in vitro. In response to our inquiry, the ZJUT team offered their suggestions to us:

Design multiple groups of sgRNAs, which could be assisted by different websites.
The GC content of the seed sequence should be controlled within 40-60%. Efforts should be made to screen for the best cutting efficiency from multiple groups of sgRNAs.
(https://crispy. secondarymetabolites.org/#/input)
Pay attention to maintain a RNase free environment during the purification process of the Cas9 protein, which could significantly affect the binding efficiency of Cas9 and sgRNA.
Refer to the commercial kit to optimize the digestion buffer.

ICII Joint preaching

ICII (Into China Into IGEM), which is sponsored by NAU-CHINA and CPU_CHINA. We held joint summer lectures with other 16 teams from all over China. Affected by the COVID-19 pandemic, our 17 teams took the form of offline decentralization and joint organization. The organizer collected the information of each team, produced all the posters of their own content, and then each team printed it out. Before the presentation, each team posted group posters on both sides of the blackboard for interested students to learn on their own.

Introduction

First of all, the iGEM team of the College of Life Science, Northeast Forestry University, discussed with our biology teacher Pengchao Wang, and decided to launch the Visible Diagnosis Platform based on G-quadruplex at 10:45 am on Wednesday, September 22, 2021, Beijing time in Room 201, Olympia College. The purpose of this presentation is to promote the knowledge of synthetic biology, popular scientific and social biological issues, and to share and discuss our 2021 project.

Preaching purpose

1) Based on the knowledge of biology, we provided students with the relevant content of the nucleic acid test for SARS-CoV-2, broaden students' horizons, cultivate their interest, stimulate their curiosity, and stimulate them to explore and think more deeply.

2) Through the popularization of general biological issues in the society, we wanted to improve students' sense of mission in defending life and awareness to maintain social justice, and cultivate social responsibility of youths who love life and science.

Preaching object

Sophomore students majoring in biotechnology, Northeast Forestry University

Preaching preparation

Prepare delicate gifts for students who participate in the presentation, let the students experience the color developing experiment in person, and grant symbolic certificates to the students who actively ask questions and participate in other activities during the presentation.

Background introduction

Multiple new COVID-19 cases were confirmed in our city, Harbin, just before our scheduled presentation. To ensure the safety of the faculty and students, we canceled the plan of holding on-site presentations, and provided a lecture in our school. We also had in-depth discussions with many students who were interested in biology.

Presenter

Hongda Fu

First of all, Hongda Fu, our team leader, briefly explained the new type of coronary pneumonia and its transmission routes, introduced general protection measures, and advised the students to wear their masks and pay attention to sanitation safety. Starting from the limitations of the current new coronavirus detection methods, he introduced to the students the advantages of our detection approach compared with the current coronavirus detection method: convenient and sensitive. In addition, our detection method has obvious color changes and visualized results; it can also guarantee high specificity and effectively avoid false positive results.

Secondly, Hongda Fu described the visual detection platform based on the G-quadruplex chain for the students to popularize science from the aspect of the experimental design. Through the design overview, the students had a taste of the beauty of the biological world, focusing on the experimental principles of the RPA selective amplification, nCas9-Phi29 strand cleavage and single strand DNA replacement, and RCA amplification of G-quadruplexes. The NEFU_CHINA2021 team members and the students participating in this presentation discussed the visual detection platform based on G-quadruplex.

In addition, Hongda Fu demonstrated the G-quadruplex color developing experiment and the use of experimental equipment to the students in the audience. We also let the them personally test the color reaction.

Finally, the NEFU_CHINA 2021 team members granted certificates to the students who were actively engaged in this event, and distributed souvenirs to all students coming to the presentation.