Liquid phase chip (suspension array, liquid chip), also known as suspension array, flow fluorescence technology, xMAP technology, is a multifunctional biochip platform developed based on the multifunctional flow dot matrix instrument developed by Luminex in the United States. It is known as the chip technology of the post-gene era. It is a collection of flow cell technology, laser technology, digital signal processing technology and traditional chemistry technology. It is a new type of biomolecular detection technology, usually used in immunoassay, nucleic acid research, enzymatic analysis, receptor and ligand recognition analysis and other research. It is also the only multi-factor detection biochip platform that has been jointly approved by authoritative institutions and the medical community for clinical diagnosis. Liquid-phase chip is a new concept of biochip. The core of this technology is to encode tiny polystyrene beads (56um) with fluorescent dyeing method, and then to encode microspheres of each color (or called fluorescent coding). Microspheres) are covalently cross-linked with probes, antigens or antibodies for specific detection substances. In application, the three-coded microspheres for different detection substances are mixed first, and then a small amount of sample to be tested is added. In the suspension, the target molecules and the molecules cross-linked on the surface of the microspheres are specifically combined, which can be simultaneously in a reaction well. Complete up to 100 different biological reactions. Finally, use Luminex TM analysis software for analysis. The instrument uses two laser beams to identify the coded microspheres and detect the fluorescence intensity of the reporter molecules on the microspheres. Because molecular hybridization or immune reaction is carried out in a suspension solution, the detection speed is extremely fast, and up to 100 indicators can be detected simultaneously in a micro-liquid reaction system. It has the technical advantages of high throughput, high speed, convenient operation, high sensitivity, strong specificity, good accuracy, and small sample amount. It is currently the only multi-factor joint diagnostic technology approved by the US FDA for marketing.

　　In November 2005, in recognition of the revolutionary contribution of this technology to the advancement of clinical diagnostic technology, Frost & Sullivan (Frost & Sullivan), an authoritative organization in the global technology industry and industry research, awarded xMAP Liquid The chip technology "2005 International Clinical Diagnosis Technology Innovation Award" marks that xMAP liquid-phase chip technology has received the most authoritative recognition for its leading position in the international clinical diagnostic technology field. On July 28, 2016, the State Council issued the "Thirteenth Five-Year National Science and Technology Innovation Plan" (Guo Fa 2016, No. 43), which mentioned in "In Vitro Diagnostic Products": "Development of fully automated nucleic acid detection systems, high-throughput liquid phase Major products such as suspension chips, medical biological mass spectrometers, and rapid pathological diagnosis systems.” On June 14, 2017, the Ministry of Science and Technology issued the “Thirteenth Five-Year Scientific and Technological Innovation Plan for Medical Devices” and proposed that “accelerate the development of microfluidic chips, single With cutting-edge technologies such as molecular sequencing, liquid biopsy, liquid-phase chips, and intelligent biosensing, we will develop a batch of early diagnosis and precise treatment and diagnosis reagents for major diseases, as well as high-precision diagnostic products suitable for primary medical institutions, and enhance the competitiveness of China's in vitro diagnostic industry." Clarified the leading position and importance of liquid-phase chip technology in contemporary biological detection technology.