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Molecular weight determination

Exact intact mass analysis of proteins or antibodies by LC-MS

PROTEIN

Molecular weight (MW) determination by LC ESI-MS protein analysis is the golden standard for proteins up to 250 kDa.

Services includes:

  • Exact molecular weight of proteins
  • Determined by UV-LC ESI-MS.
  • Accuracy 10 ppm (+/- 1 Da for 100 kDa protein)
  • All peaks in the chromatogram are deconvoluted to provide exact masses of all proteins within each peak
  • Finally, comparison of data with theoretical MW of protein

Applications:

The MW of protein isoforms and correlation with the protein sequence enables detailed understanding of the protein heterogeneity.
Furthermore, the MW of co-eluting proteins and integration of HPLC peak areas allows semi-quantitative analysis of protein contaminants and degradation fragments.

  • Detect both protein oxidations and deamidation
  • Glycoprofile characterization
  • Identify contaminating proteins not well separated by UV-HPLC (coeluting proteins or shoulders etc.)
  • Stability study – characterize degradation products
  • Drug substance batch comparison

ANTIBODY

The analysis can be conducted with and without reduction, before and after removal of N-glycans and after enzymatic cleavage into specific sub-units.

Services include:

  • Exact mass of intact mAb
  • Reduction and MW determination of heavy and light chain
  • Removal of N-glycans and intact mass of deglycosylated forms
  • IdeS cleavage and MW determination of sub-units
  • Finally, comparison of data with theoretical masses

We also offer a range of other monoclonal antibody characterization services. For example: • Disulfide analysis.• Peptide mapping of antibodies. • De-novo sequencing of antibodies • Glycosylation analysis.

Send us a request so we can adjust the analysis to meet your specific needs.

Services
Molecular weight analysis

Protein Molecular Weight Determination

  • Mass range 0-250 kDa
  • Sample amount >5 ug
  • Accuracy within 30 ppm

$900.00

Fast and Easy
Will be delivered in 4-8 days
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Molecular weight analysis

Exact molecular weight of mAb including deglycosylation

  • Exact MW of intact antibody
  • Reduction and deglycosylation of antibody
  • Exact MW of heavy and light chain and deglycosylated forms
  • Comparison with the expected masses

$2,700.00

Convenient Service
Will be delivered in 10-20 days
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Molecular weight analysis

Mw of peptides by custom UV-LC MS

  • UV-LC trace and exact MW of proteins above 1%
  • Customized UV-LC ESI-MS method; eg. column, gradient, MS conditions
  • Accuracy +/- 2.5 Da
  • Comparison with theortical MW of protein

Customized Service
Quality analysis, presented in easy-to-understand reports
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Molecular weight analysis

Mw of proteins in drug sample by custom UV-LC MS

  • UV-LC trace and exact MW of proteins above 1%
  • Customized UV-LC ESI-MS method; eg. column, gradient, MS conditions
  • Accuracy +/- 2.5 Da
  • Comparison with theortical MW of protein

Customized Service
Quality analysis, presented in easy-to-understand reports
Info / Order
Request quote

By ESI-MS analysis, the sample in liquid phase are sprayed through a capillary at high voltage into the MS instrument where the mass over charge ratio (m/z) is measured. For large biomolecules the electrospray process results in multiply protonated molecules with a distribution of ion species at m/z range from 1-3000. The mass of the molecule is determined using a deconvolution algorithm that calculates the mass of the intact non-protonated protein, peptide or antibody. The ESI process requires that the sample preparation is quite pure without interfering salts or detergents.

The sample is purified by reversed phase HPLC (Agilent 1200 system) using a short C8 column before being analyzed on a Q-TOF mass spectrometer (Bruker Maxis Impact system). The mass of the sample is determined by deconvolution of the obtained raw spectra using the MaxEnt algorithm. The high resolution and accuracy of the Q-Tof instrument result in very accurate mass determination within 0-3 Da of the theoretical mass.

For antibodies the sample is analyzed in the intact form and after reduction with DTT.

Sample Preparation Guidelines
Antibody samples can be submitted in liquid or as lyophilized material.
The chromatographic purity should be >90%.
Avoid detergents and keep buffer concentration at a minimum. LC-ESI MS analysis can be done on samples containing small amounts of salts, urea or detergent, but the best result are obtained with low buffer strength in volatile solvents without detergents.

Minimum sample amount: ~ 10-50 microgram protein, ~ 100 microgram antibody

Put the protein/peptide/antibody into a microcentrifuge tube.
Use Eppendorf Safe Lock tubes, or similar tubes from your lab.
Lyophilize or speed vac the antibody to a solid sample to ensure stability during shipment.
Alternatively, freeze the liquid sample for cold shipment.

Attention
Please note that MW determination of intact proteins/antibodies by mass spectrometry CANNOT be conducted on samples from gels or PVDF membranes!

shipping
Ship your protein samples by a courier company of your own choice

Place your samples into micro tubes and pack in a suitable transport box. Remember to print and include the sample submission form.

  • Contact a courier company of your choice (FedEx, UPS, DHL, TNT, World Courier etc.). Use the following sentence to describe the content: “Protein material – Non-toxic, non-hazardous, for research purpose only“.
  • Use cool packs or cooling units if your samples should be stored below 5°C/40°F
  • Ship the samples to the office closest to you (Canadian customers, please ship to Europe):
Customers in the USA
Alphalyse, Inc.
200 Page Mill Road, Suite 100
Palo Alto, CA, 94306
USA
Att: Jette Williams
Tel: (650) 543-3193
Customers outside of USA
Alphalyse A/S
Unsbjergvej 4 D
DK-5220, Odense
DENMARK
Att: Anette Rasmussen
Tel: +45 6310 6500
shipping
Order a prepaid FedEx Air Waybill < 1 lb./ 500g

A prepaid FedEx Air Waybill can be used for fast and easy shipment of samples in packages up to 1 lb./ 500g.
We will generate a prepaid Air Waybill, prefilled with the correct information, and send it to you by e-mail (PDF-format) within 24 hours.
Then follow these simple instructions:

  • Place your samples into micro tubes. Pack in suitable transport box. Remember to print and include the sample submission form.
  • Print the PDF document and stick it on the transport box or just hand it to your FedEx officer upon pickup.
  • Call to request a pickup from your local FedEx office.

If you plan to send your samples stored at room temperature, this option is usually the right choice. If you fill your box with cooling packs, the weight will most often exceed 1 lb./500g.

shipping
Order a prepaid FedEx Air Waybill < 10 lb./5kg (e.g. for packages with cooling packs)

This prepaid FedEx Air Waybill can be used for shipment of samples in packages up to 10 lb./ 5kg, with or without cooling packs (do not use dry ice!).
We will generate a prepaid Air Waybill, prefilled with the correct information, and send it to you by e-mail (PDF-format) within 24 hours.
Then follow these simple instructions:

  • Place your samples into micro tubes. Pack them in a suitable transport box. Remember to print and include the sample submission form.
  • Fill with cooling units/cold packs (do not use dry ice!).
  • Print the PDF and stick it on the transport box or just hand it to your FedEx officer upon pickup.
  • Call to request a pickup from your local FedEx office.

If you plan to fill your transportation box with cooling packs, select this shipping option. If you plan to use dry ice, you cannot use this Waybill!

shipping
Get a quote for shipment by World Courier

The World Courier service can be used for shipment of samples of all types. If you select this option, we will contact you to provide a quotation based on location and shipping conditions. You will receive a prepaid Air Waybill which will be invoiced together with your analysis results. This is usually a good option if FedEx does not service your location.
With the prepaid World Courier service you get:

  • GxP compliant processes to ensure maximal security and traceability
  • Door-to-door solution on a dedicated vehicle
  • Possibility of providing qualified packaging, temperature monitoring and dry ice
  • Shortest possible transit-time through “next flight out”-procedure
  • Customs clearance and help with paperwork
Order analysis now
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