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Intact protein mass analysis 0-250 kDa

Molecular Weight Determination by LC-MS

PICK ‘n POST™ molecular weight determination by LC-ESI-MS protein analysis for proteins up to 250 kDa

Our ESI-MS intact mass service can be used to:

  • Determine the mass weight of peptides and proteins in your sample up to 250 kDa.
  • Compare samples – batch to batch variation.
  • Determine purity of your sample.
  • Look for modification such as glycosylations, acetylations, oxidations, etc..

The accuracy is within 30 ppm (+/-3 Dalton for a 100 kDa protein).

We provide this service as PICK ‘n POST™ which means that you can expect your results in 4-8 days.

How-to-order-PICK-n-POST

When would I choose ESI-MS protein analysis over MALDI-MS?

You should select ESI-MS protein analysis when you want to determine the mass weight of peptides and proteins in your sample above 50 kDa.

If you have further needs

  • You want detailed information about exact molecular weight of several proteins in your sample.
  • You want information about post translational modifications.

Send us a request, so we can enter dialogue with you and meet your specific needs.

Services/Products
IIntact mass weight by ESI or Maldi

PICK ‘n POST™ intact mass by ESI-MS

  • Intact Mw analysis by ESI-MS
  • Mass range 0-250 kDa
  • Accuracy within 30 ppm
  • Sample amount >5 ug

$450.00

Fast and Easy
Will be delivered in 4-8 days
Info / Order
Request quote
IIntact mass weight by ESI or Maldi

PICK ‘n POST™ intact mass by ESI-MS – comparison with protein sequence

  • Intact Mw analysis by ESI-MS
  • Comparison with theoretical Mw
  • Mass range 0-250 kDa
  • Accuracy within 30 ppm
  • Sample amount >5 ug

$650.00

Fast and Easy
Will be delivered in 4-8 days
Info / Order
Request quote

Technical details

Introduction
By ESI-MS, proteins and peptides 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 or peptide. 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.

Sample requirements

Sample Preparation Guidelines
Protein samples can be submitted in liquid or as lyophilized material.
The chromatographic protein 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 amount ~ 10-50 micrograms

Put the protein/peptide into microcentrifuge tube
Use Eppendorf Safe Lock tubes, or similar tubes from your lab
Lyophilize or speed vac the protein to a solid sample to ensure protein stability during shipment
Alternatively, freeze or refrigerate to +4°C for cold shipment of the liquid sample

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

Sample shipment

shipping option
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.

  • 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 option
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.
  • 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 option
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.
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. Fill with cooling units/cold packs.
  • 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.

shipping option
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

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