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Protein Molecular Weight Testing Services

KMD Bioscience has a complete technical service platform, experienced scientific research team, advanced experimental conditions, to provide customers with personalized solutions to meet the needs of customers to detect protein molecular weight. In proteome research, the determination of protein molecular weight plays a large role in the fields of amino acid sequence determination, unknown structure determination, medcine development, and medcine metabolism analysis.

Molecular weight is one of the main characteristic parameters of proteins, the correct molecular weight often represents the correct structure of the measured organic compounds and biological macromolecules. Molecular weight is also the primary parameter in the identification of peptides, proteins, etc., and is also one of the important data for the approval of genetic engineering products. With the rapid advancement of the genome project, protein molecular sizing has received more and more attention. Traditional detection methods have poor accuracy, low sensitivity, greatly affected by external factors. In recent years, biological mass spectrometry technology is increasingly mature, more and more applied to molecular weight detection, the current common mass spectrometer is electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-Q-ToF) and matrix-assisted laser analytical ionization time-of-flight mass spectrometry (MALDI--ToF), the main difference is shown in the figure below. 


Mass Spectrometer Model


ESI-Q-ToF mass spectrometer

* Using ESI as an ion source to generate multi-charge peaks, the molecular weight of the protein is calculated by convolution

* High sample requirements, high salt or buffer-containing samples are easy to form matrix effects

* Suitable for the analysis of polar compounds that are difficult to volatile and have poor thermal stability

* The cost is relatively high

MALDI - ToF mass spectrometer

* Using MALDI as an ion source, it mainly produces single-charge peaks and few fragment peaks, also uses complex mixtures for analysis

* Low sample requirements, resistant to high concentrations of salts, buffers and other non-volatile components

* Relatively low cost



KMD BIOscience can provide protein molecular sizing services based on MALDI-TOF mass spectrometry. The MALDI-TOF mass spectrometer consists of two main parts: the matrix-attached laser desorption ionization ion source (MALDI) and the time-of-flight mass analyzer (TOF). The principle of MALDI is the process of ionizing biomolecules by irradiating the sample with a laser to form a crystalline film with a matrix, and the matrix absorbs energy from the laser and transmits it to the biomolecules. The principle of TOF is that ions are accelerated through the flight pipeline under the action of an electric field, and are detected according to the different flight time reaching the detector, that is, the mass-to-charge ratio (M/Z) of the ion is determined to be proportional to the flight time of the ion, so as to realize the detection of ion. The accuracy of MALDI-TOF is as high as 0.1%-0.01%, and the molecular weight of biomacromolecules can currently be determined in the range of 700-600000Da. 



Service Process:   



Sample Delivery Requirements:    


--Sample volume: 10-50ug


--Non-gel samples: volatile salt < 20mM, no PBS, SDS and urea, etc

--Glue samples: glutaraldehyde was not used as a fixative in the silver dyeing process

--Storage and transportation: Liquids are recommended to be stored at low temperatures, and glues are treated with deionized water to prevent drying


Service Advantages:  


--Low sample consumption and low cost

--High sensitivity, high accuracy, fast measurement speed

--Suitable for complex sample determination

--Enables large-scale protein molecular weight determination


How to Order?


If you are interested in our services, please call us directly at +86-400-621-6806 or send an email to