face

Intact protein mass analysis 0-50 kDa

Molecular Weight Determination by MALDI MS

We offer PICK ‘n POST™ molecular weight determination by MALDI-MS for proteins below 50 kDa

Does your protein or peptide weigh below 50 kDA? Then we use MALDI-MS analysis to determine the intact mass weight.

You can use the service to

  • Compare samples – for example batch to batch variation.
  • Determine the purity of your sample.
  • Look for modification such as glycosylations, acetylations, oxidations, etc.
  • Compare with theoretical Mw.

The accuracy on this service lies within 50 ppm (+/- 1 Dalton for a 20 kDa protein).

We offer this services as PICK ‘n POST with results in 4-8 days. The report lays out the data in a way that is easy to read and understand.

How-to-order-PICK-n-POST

What is the advantage of MALDI-MS compared to the ESI-MS?

The main advantage is that the full mass spectrum can be interpreted without any deconvolution step. We use ESI-MS for proteins up to 250 kDa.

Examples from data report

Services/Products
IIntact mass weight by ESI or Maldi

PICK ‘n POST™ intact mass by MALDI-MS

  • Intact Mw analysis by MALDI-MS
  • Mass range 0-50 kDa
  • Accuracy within 50 ppm
  • Sample amount >5 ug

$300.00

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 MALDI-MS – comparison with theoretical Mw

  • Intact Mw analysis by MALDI-MS
  • Comparison with theoretical Mw
  • Mass range 0-50 kDa
  • Accuracy within 50 ppm
  • Sample amount >5 ug

$500.00

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

Technical details

Introduction
In MALDI MS, the dissolved sample is deposited on a metal target and the peptides and proteins are co-crystallized with a light-absorbing matrix. A laser beam is directed at the dry matrix sample, the sample molecules are desorbed and ionized and the masses are measured in a time-of-flight (TOF) mass analyzer. Proteins are observed in the mass spectrum (mass-over-charge spectrum, m/z) as singly (m/z MH+) as well as multiple charged ions.

Sample preparation and data analysis
Sample is mixed with 2,5-dihydroxyacetonphonone/diammonium hydrogen citrate (DHAP/DAHC) matrix and spotted onto a Big Anchor target from Bruker. Mass spectra are acquired on an Autoflex Speed MALDI TOF/TOF mass spectrometer in linear mode using Compas 1.4 control and processing software. The mass spectra are calibrated by external quadratic calibration using Bruker Protein Calibration Standard 1. The sample mass is calculated from the least charged ion within the calibrated range of the mass spectrum.

Sample requirements

Sample Preparation Guidelines
Protein and peptide samples can be submitted in liquid or as lyophilized material.

The chromatographic protein/peptide purity should be >90%
Avoid detergents and keep buffer concentration at a minimum. MALDI-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 0.5 or 1.5 mL 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 SDS gels or from 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

Read more
Order analysis now
Newsletter Subscribe to the Alphalyse Newsletter to get 3 tips
about protein analysis methods and applications
Private, secure, spam-free
© Copyright Alphalyse , Inc. 2002 - 2017. All rights reserved.