On this day, 35 years ago, on November 25, 1990 (October 9, 1990, the lunar calendar), Chinese scientists directly discovered the new structure of deoxyribonucleic acid. In November 1990, the Institute of Chemistry of China Academy of Sciences directly observed the new pigtail-like structure of three-chain deoxyribonucleic acid for the first time in the world. Relevant experts evaluated this as another major discovery in human understanding of nature. Deoxyribonucleic acid is the main material basis for organisms to store, replicate and transmit genetic information, so scientists regard it as one of their main targets when exploring the mysteries of life sciences. In 1989, American scientists used scanning tunneling microscopy to directly observe double-helix deoxyribonucleic acid, confirming the existence of double-helix deoxyribonucleic acid indirectly observed using X-ray diffraction. The new structure of three-chain deoxyribonucleic acid was discovered using a scanning tunnel microscope in a laboratory led by 37-year-old researcher Bai Chunli. Before they achieved this major achievement, similar structures were only speculated by some foreign scientists as indirect results using other techniques. What is significant is that the direct discoverer of three-chain deoxyribonucleic acid is precisely the laboratory led by Bai Chunli, the developer of the Scanning Tunnel Microscope of the Institute of Chemistry. This precision instrument with atomic-level resolution was first successfully developed in my country by the Institute of Chemistry and other units in 1987 through self-reliance. Relevant scientists believe that this discovery not only shows that scanning tunneling microscopy has great future in studying biological materials, but also finds a major breakthrough in understanding the helix structure of deoxyribonucleic acid.