U.S. researchers make the most complex biochemical circuit to date

Xinhua News Agency, Washington, June 2 - The California Institute of Technology researchers used artificially synthesized DNA (DNA) molecules to make the most complex biochemical circuits ever produced in vitro. Researchers say that the purpose of designing such a circuit is not to compete with the electronic computer, but to explore the principles of biological systems processing information.

In a traditional computer, the logic gates of the basic components of an integrated circuit are made of transistors, but in this newly made biochemical circuit, the logic gates consist of short single-stranded DNA and partially double-stranded characteristic DNA. The transistor flows in and out of the transistor as the signal, while the DNA logic gate receives and emits the signal as a signal.

The researchers reported in the latest issue of the journal Science that they designed multiple circuits, the largest of which included 74 different DNA molecules that could calculate the square root of integers no greater than 15 and gave an answer less than The largest integer of square root. The researchers read the calculated answer by monitoring the concentration of the output signal molecules in the test tube solution. The entire calculation process takes about 10 hours.

The researchers said that designing biochemical circuits with decision-making capabilities can help better control the molecular responses used in bioengineering, chemical engineering, and biochemical industries. For example, in the future, a biochemical circuit designed and synthesized can be placed in a clinical blood sample to measure the level of various molecules in the sample, and then make a pathological diagnosis based on this information.

"We tried to borrow concepts that have brought great success to the electronic world, such as the abstraction of arithmetic, programming languages, and compilers, and apply them to the world of molecular biology," said the paper's first author, the Department of Bioengineering of California Institute of Technology. Postdoctoral Qian Yu said.

The biochemical circuits previously manufactured in the laboratory were generally limited because the stability and predictability of the work were reduced as the size of the circuit was increased. Qian Yu explained that the most likely reason for this limitation is that different circuit functions need to be implemented with different structural molecular components, so that when the circuit becomes larger and larger, the difficulty of manufacturing and debugging also increases. The increase. In the newly designed circuit of this design, the structure of the molecular element is very simple and standardized, and the operation is stable and easy to upgrade.

Qian Hao said that in the computer industry, everyone is trying hard to build better and better computers. “We are also making the same efforts. We are going to make better and better biochemical circuits to accomplish more advanced tasks, so that molecular equipment is based on Their environment and action."