Molecular weight is a fundamental physicochemical property parameter of organic compounds. The correctness of molecular weight often signifies the correctness of the structure of the organic compound and biological macromolecule being measured. Molecular weight is also a primary parameter in the identification of peptides and proteins and is crucial data for the approval of genetically engineered products.
Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF-MS) is a new type of soft ionization mass spectrometry developed in recent years. It features low sample consumption, high sensitivity, fast measurement speed, easy implementation of high-throughput analysis, and the ability to identify proteins on a large scale and measure the molecular weight of biological macromolecules. It provides a powerful analytical tool for protein research. The simplicity, intuitiveness, and direct measurement of macromolecular mixtures with minimal fragmentation peaks are the advantages of MALDI-TOF-MS. Therefore, this technology is widely used in the molecular weight determination of biological macromolecules. The MALDI-TOF-MS instrument mainly consists of two parts: the matrix-assisted laser desorption ionization ion source (MALDI) and the time-of-flight mass analyzer (TOF). The principle of MALDI is to use laser irradiation on the co-crystallized thin film formed by the sample and the matrix. The matrix absorbs energy from the laser and transfers it to the biomolecule, causing the biomolecule to ionize. It is a soft ionization technique suitable for mixtures and biological macromolecule determination. The principle of TOF is that ions are accelerated through a flight tube under the influence of an electric field. The time of flight to the detector is measured, which is proportional to the mass-to-charge ratio (M/Z) of the ions, thus enabling ion detection. The accuracy of MALDI-TOF is as high as 0.1%-0.01%, which is far superior to conventional SDS-PAGE and high-performance gel chromatography techniques. Currently, it can measure the molecular weight range of biological macromolecules from 700 to 600,000 Da.
BiotechPack Company uses Bruker's ultrafleXtreme™ MALDI TOF/TOF mass spectrometry system to provide molecular weight measurement services for biomolecules to researchers. This system is used to analyze the molecular weight of target proteins or peptides, detect protein dimers, and provide a general assessment of sample purity.
Sample Requirements
1. The required sample amount is approximately 10-50µg;
2. Sample purity >90%;
3. During sample preparation, avoid using surfactants such as SDS and Triton-X as much as possible. Also, try to lower salt concentrations such as Tris;
4. If you must use surfactants and high salt concentrations during sample preparation, we will first remove these compounds through related experiments upon receiving your sample, then proceed with molecular weight determination.
Sample Transportation
1. We recommend freeze-drying the sample before shipping, as proteins in freeze-dried samples are very stable.
2. For liquid samples, we recommend shipping with dry ice. For short-distance transport, ice packs are also acceptable.
Notice
Gel particle samples or samples transferred to PVDF membranes are not suitable for molecular weight determination experiments.
Research Cases
In the application of MALDI-TOF, besides detecting the molecular weight of the sample, it can also provide information on the sample's purity. As shown in the figure below, a significant signal peak appears within the theoretical molecular weight range of 1046.6 Da, indicating good sample purity.
Molecular Weight Measurement Research Cases
Bilingual Project Report (Chinese/English)
In the technical report, BiotechPack provides a detailed bilingual (Chinese and English) technical report, including:
1. Experimental procedures (in Chinese and English)
2. Related mass spectrometry parameters (in Chinese and English)
3. Mass spectrometry images
4. Raw data
5. Results of protein molecular weight and purity analysis
One-Stop Protein Molecular Weight Measurement Service
You only need to place an order and send your samples
BiotechPack's one-stop service includes: sample processing, machine analysis, data analysis, and project report
