The full name of mass spectrometry is surface-enhanced laser desorption ionization time-of-flight mass spectrometry (seldi-tof or seldi). Mass spectrometry technology – flight mass spectrometry is a special chip invented by Tanaka, the winner of the Nobel Prize in Chemistry in 2002 and manufactured by ciphergen system biology company. .
Working principle
The early flight mass spectrometry was matrix-assisted laser desorption ion flight mass spectrometry (maldi-tofms). seldi changed the matrix to a protein chip designed with the principle of chromatography, which enhanced the separation ability. Chip technology was originally applied to DNA analysis, called gene chip. Because the chip integrates a variety of high-tech technologies: high integration, ultra-micronization, computerization, and automation, it has the advantages of variety and rapidity, and has become the first choice for flight mass spectrometry. Unlike DNA, proteins are three-dimensional structures. The most difficult part of making protein chips is how to separate certain proteins by immobilizing them on the chip surface without compromising the function and increasing the background. In view of the difficulty of solving this problem with traditional techniques, in the detection system of mass spectrometry in flight, the surface of the protein chip is chemically (cationic, anionic, hydrophobic, hydrophilic, and metal ion integration, etc.) or biochemically (antibody, receptor, etc.) according to the principle of chromatography. , DNA, etc.), the chip specifically binds to the determined protein in the serum, and then selectively washes to obtain a high-resolution retained protein spectrum (the first separation). When energy-absorbing molecules (eams) are added, the proteins retained on the chip form crystals. After the specific laser irradiation, the crystal dissociates, the charged molecules are accelerated when passing through the electric field, and the recorder records the length of the flight time. , the shorter the flight time. The signal is converted and recorded by a high-speed analog-to-digital converter, and the protein being measured is presented as a series of peaks, and these specific peaks can be regarded as the fingerprint of the disease. The position of individual proteins on the spectrum depends on the time of flight. seldi comes with unique software that can process and analyze large amounts of information quickly. The horizontal axis of the mass spectrum of the protein peaks analyzed by seldi represents the protein type, and the vertical axis represents the intensity and abundance of the protein. Quantitative determination was performed. Using mass spectrometry in flight can uncover new disease protein profiles that could not be separated and detected in the past. Based on several years of use around the world, the method is generally considered to be fast, reproducible, and capable of detecting trace amounts of protein.
Clinical application
The technology of flight mass spectrometry has been widely used in many diseases, such as cancer, geriatric diseases, infectious diseases, cardiovascular diseases and nervous system diseases. The researchers used seldi to detect metastatic melanoma, sarcoma, and kidney cancer with 87 percent sensitivity. They believe that the method can be used for the diagnosis of various cancers, such as liver cancer, prostate cancer, breast cancer, bladder cancer, and esophageal cancer, based on the unique 8-24 protein fingerprints, with a detection limit of femtomol/L. According to reports, Washington Elizabeth Hospital used this technology to detect lung cancer with a sensitivity of 98% and a specificity of 97%; the Hopkins School of Medicine detected ovarian cancer with a sensitivity of 82% and a specificity of 98%; Hopkins Medicine The hospital and the National Cancer Institute of the United States cooperated to detect breast cancer, with a sensitivity of 93% and a specificity of 91%. Domestic research has also achieved remarkable results, and the results are very surprising. All statistical indicators are far better than the classic tumor markers. Many scientists believe that the discovery of seldi is very exciting and has great potential for clinical application. seldi will discover many new tumor markers and make breakthroughs in tumor research.
Prospect
Although it has only been 4 years since the launch of seldi, and it has only been more than two years since the first officially published work report, judging from the results of worldwide application, seldi has extremely bright applications in the diagnosis of many diseases, especially in the early and accurate diagnosis of tumors. prospect. More than 300 researchers working in the life sciences or medical front lines of the US Scientific Advisory Board generally believe that flight mass spectrometry is a very promising application technology, which will bring a revolution or innovation to diagnostics, and greatly change some current diseases such as tumors, Conditions such as cardiovascular disease that are underdiagnosed have a bright future.
