The mass spectrometry resource supports research projects that require determination of peptides and proteins sequences, oligosaccharides, and polymers or biopolymers structural characterization. Analyses are carried out using Matrix Assisted Laser Desorption Ionization with time of flight, with automated tandem analysis of selected ions, mass spectrometry (MALDI-TOF/TOF).  The mass spectrometric data from peptides resulting from enzymatic digestion of specific proteins (peptide mass fingerprint) are search against databases using the GPS Explorer^TM Software with the Mascot® Search Engine.  Association of the mass spectrometer instrument with a Nano/Capillary flow HPLC result in a LC/MS-MS type of analysis.

Contacts:

Alberto Nuñez Ph.D., Chemist

Voice (215) 233-6639

e-mail: alberto.nunez@ars.usda.gov

Laurie Fortis, Biologist

Voice (215)233-6759

e-mail: laurie.fortis@ars.usda.gov

FAX:    (215) 233-6796

Request forms:

Request forms and sample processing protocols can be downloaded in PDF format:

• Request form
• Sample protocols
• MALDI spotting grid

FTP site (Password Required)

To gain access to your data, please contact the facility supervisor.

Instrumentation:

4700 Proteomics Analyzer - MALDI-TOF/TOF: This instrument offers a high power resolution (FWHM = 20,000) with a mass accuracy of >50 ppm across the plate with external calibration and >2 ppm with internal calibration.  The ability to obtain Peptide Mass Fingerprints (PMF) combined with tandem mass spectrometry (MS/MS) of selected peptides provide a powerful tool for proteins and peptides identification though database searching or de novo sequencing.  The instrument is associated with the Mascot® automated database search software for proteins identification.  MALDI-TOF-TOF analysis is also extended to oligosaccharides and polymers.

AB 4700 Proteomics Analyzer with 4700 Explorer Software

Associated Instrumentation:

LC-Packings HPLC/Nano-Capillary flow for 1D and 2D separation of peptides, with robotic spotting (Probot) on MALDI plates.

LC Packings Famos, Switchos, and Ultimate

LC Packings Probot

Beckman-Coulter PF2D for 2 D protein HPLC chromatographic separation

2-D Gel Electrophoresis

epMotion Eppendorf 5075 Liquid Handling Station