High-Resolution Mass Spectrometry Molecular Weight Identification

The mass spectrometry widely used for protein identification currently includes two types: one is MALDI-TOF, which directly measures molecular weight; the other is LC-MS, which performs high-resolution mass spectrometry on multiple charged signals obtained by electrospray, followed by deconvolution analysis of the signals to obtain precise molecular weight values. Each method has its advantages and applicable fields. Biotech Paker BioTech is equipped with both mass spectrometry systems, which can be used for molecular weight determination of various protein samples, meeting various protein molecular weight analysis needs, including peptide fingerprinting and protein identification.

ESI ion spray molecular weight determination

 

Case Analysis:

1 Precise molecular weight determination of a protein drug with a molecular weight greater than 10KDa
Biotech Paker collects the original signals directly using the Q Exactive mass spectrometer after online reverse-phase chromatography separation. Then, ProMass for XcaliburTM is used to perform deconvolution calculation on the original data to obtain the precise molecular weight of the sample.

A UV detector is connected during the reverse-phase chromatography separation process before entering the mass spectrometer (as shown in the figure below), which evaluates the sample's purity while achieving sample separation; the chromatography separation process also reduces the requirement for sample purity in precise molecular weight detection.

 

High-resolution mass spectrometry molecular weight - Biotech Paker BioTech

When analyzing the original mass spectrometry data using software, the molecular weight of the main and minor components in the sample can be selected and analyzed according to TIC (Total Ion Chromatogram).

For example, to analyze the molecular weight of the main component marked in the red box in the figure above, we only need to find the mass spectrometry original data obtained at that moment (as shown in the figure below).

 

Mass spectrometry original data - Biotech Paker BioTech

Then, the above original data is deconvoluted to obtain the precise molecular weight of the main component in the protein sample (as shown in the figure below).

 

Precise molecular weight

2 Precise molecular weight determination of a peptide drug with a molecular weight less than 10KDa
Biotech Paker BioTech collects the original signals directly using the Q Exactive mass spectrometer after online reverse-phase chromatography separation and then directly calculates the original data using the classical method of molecular weight calculation to obtain the precise molecular weight of the sample.
A UV detector is connected during the reverse-phase chromatography separation process before entering the mass spectrometer (as shown in the figure below), which evaluates the sample's purity while achieving sample separation; the chromatography separation process also reduces the requirement for sample purity in peptide precise molecular weight detection.

In the process of calculating precise molecular weight of the peptide, we only need to find the mass spectrometry original data at the elution time point of the peptide (as shown in the figure below)

According to the classical method of molecular weight calculation, the molecular weight of molecules with two or more charges is calculated to obtain the precise molecular weight of the peptide sample.

At the same time, we will provide you with the original mass spectrometry data of high-abundance charged ions for reference (as shown in the figure below).

Comparison of the advantages and disadvantages of MALDI and ESI:

A UV detector is connected during the reverse-phase chromatography separation process before entering the mass spectrometer

In the technical report, Biotech Paker will provide you with a detailed bilingual (Chinese and English) technical report, including:

1. Experimental steps (Chinese and English)
2. Relevant mass spectrometry parameters (Chinese and English)
3. Mass spectrometry images
4. Original data
5. Protein/peptide molecular weight information

One-stop service for high-resolution mass spectrometry molecular weight determination

You just need to place an order - send samples
Biotech Paker's one-stop service completes: sample processing - on-machine analysis - data analysis - project report

Related services

Molecular weight determination
MALDI TOF molecular weight analysis
Protein molecular weight determination
Molecular weight determination of protein complexes, protein and small molecule complexes