MS Analysis Expert

In the field of proteomics research, liquid chromatography-mass spectrometry (LC-MS/MS)-based discovery proteomics can detect and relatively quantify thousands of proteins in biological samples over the past decade or two. It has been widely used in various research, and reseaechers have developed two mainstream methods, label quantification (iTRAQ/TMT, SILAC) and label free, which are based on data-dependent acquisition (DADA). The method of collecting protein spectral data is also referred to as "shotgun". However, the DDA data acquisition mode has inherent shortcomings such as poor repeatability, inaccurate quantification, large data loss, and difficulty in detecting low abundance proteins. MRM /SRM/PRM-based target proteomics can provide accurate absolute quantitative results for tens to hundreds of target proteins with high repeatability and is the gold standard for absolute quantitation of mass spectrometry. However, the flux is relatively low, and accurate quantitati...

Read   Effects of Glycosylation on the Stability and Half-life of Antibody Drugs Effects of Glycosylation on the Safety of Antibody Drugs The Critical Quality Attributes   (CQA) of antibody is the standard to judge whether it is qualified. CQA   must be in a proper range to ensure the effectiveness of drugs, and more importantly, the safety of drugs. By affecting the effect function of F c  end, glycosylation modification of F c  end will affect the safety of antibody, which is manifested in immunogenicity, PK/Pd (pharmacokinetics/pharmacodynamics), etc. The development of antibody has experienced mouse antibody, chimeric antibody, humanized antibody, and then to the last all human antibody, throughout which the immunogenicity of antibody has been constantly reduced. For glycosylation , human cells specifically synthesize Neu5Ac sialic acid, while other mammalian cells can not only synthesize Neu5Ac sialic acid, but also synthesize Neu5Gc sialic a...

Among various post-translational modifications of proteins, glycosylation is one of the most important and complex modifications, and it is also one of the key quality attributes to evaluate antibodies. The realization of the function of monoclonal antibody is closely related to its glycosylation, which will affect the performance of protein, such as conformation, stability, solubility, pharmacokinetics, activity and immunogenicity. Glycosylation is one of the important post-translational modifications of proteins. According to the modified sites of glycosylation, it can be divided into N-glycosylation and O-glycosylation. N-glycosylation is located in asn-297. N-acetylglucosamine in oligosaccharide links itself with  amide nitrogen on asparagine residue  to  modify   protein ,which start s  from endoplasmic reticulum and complete s  in Golgi body .  O-glycosylation is completed in Golgi body by n-acetylgalactose in oligosaccharide linking with ...

Types of Commonly U sed M ass S pectrometer s The subjects of biological research are generally complex macromolecules, including proteins, nucleic acids, sugars, lipids, and various small molecules. The nature of various types of biomolecules also varies widely. Therefore, various  types of mass spectrometers  are  used in biological research. The c ommon used ones  for biological research  include quadrupole mass spectromete r, t ime of f light m ass s pectrometer , ion trap mass spectrometer an d i on cyclotron resonance   mass spectrometer . Time of Flight Mass Spectrometer (TOF) The mass-to-charge ratio of ions determined by this type of mass spectrometer is derived by analyzing the time of flight of the ions in the vacuum flight tube. After continuous improvement, the TOF mass spectrometer has greatly improved in resolution and precision. The accuracy can reach PPM level after the post-correction procedure, and the detected ion mass range...

As a commonly used technology in biological research today, mass spectrometry is becoming increasingly  important in biological research by quickly and efficiently measuring the advantages of complex biological macromolecules and small molecules. Mechanism of M ass S pectrometry Mass spectrometry  analysis   is a method of analyzing a sample by measuring and analyzing the mass-to-charge ratio of the sample ions. The mass spectrometer is roughly divided into three parts , ion source, mass analyzer, and detector. The mass analyzer is the core component of the mass spectrometer, which determines the sensitivity, resolution, ability to generate ion fragments, and accuracy of the mass   spectrometer.   Before the sample is analyzed, it is first ionized in order to bring a certain charge to the sample molecule. Next, the charged ions  will  first driven through an accelerated electric field and fly into an analytical electric or magnetic field. Due ...

As a commonly used technology in biological research today, mass spectrometry is known as one of the most popular   techniques  in biological research by  quickly and efficiently measuring the advantages of complex biological macromolecules and small molecules. The History of M ass S pectrometry The first mass spectrometer ,  invented by J. J. Thomson , has been around for more than 90 years . It was mainly used for the determination of inorganic elements in chemical experiments. With the development of mass spectrometry technology  and computer technology,   mass spectrometer has gradually been applied in the analysis of more complex biomolecules, including amino acid , protein, lipids, sugar and so on. Although the history of mass spectrometry and the time it has been applied to biological research are much shorter than those of microscopes, the importance of mass spectrometry in biological research is irreplaceable as a n  accurate   m...