Protein Core Services
Before any work can be carried out, an account must be set up. To initiate this, please fill out the on-line account form. For routine services, like mass spectrometric analysis, protein identification etc., please fill out the online submission forms PRIOR to dropping off the samples. For other services, like interaction discovery, molecular interaction analysis, protein expression etc., please first fill out the on-line form. Dr. Seeholzer will then contact you to schedule a consultation to initiate the work and discuss proper preparation of samples and cost of services. For all services that require consultation, please look for the appropriate submission guidelines and read carefully before the consultation meeting.
Protein Expression: We offer expression of recombinant proteins in bacteria and insect cells (baculovirus). We have a variety of vectors available for recombinant protein expression. Please consult with Steven Seeholzer for more details.
Discovery: The PCF has a Ciphergen PSIIc SELDI
(Surface Enhanced Laser Desorption Ionization – Time
Of Flight) mass spectrometer. This device combines the advantages
of selective immobilization of bait molecules on chemically
derivatized surfaces with MALDI-MS. It is possible to immobilize
recombinant proteins, antibodies, nucleic acids, and certain
Applications include: interaction discovery, expression difference mapping, biomarker discovery, and protein profiling. With few exceptions, the SELDI mass spectrometry experiments will be done on a full-service basis by the PCF staff.
Chromatography: We have 3 chromatographic systems available for general use, including one that operates at 4°C. Many purification options, including standard reversed phase, affinity, and ion-exchange are available. The chromatography systems are available on either a user-operated or a full service basis.
MALDI-MS: Protein mass spectra as well as PMF (Peptide Mass Fingerprint) are available. In-gel proteolytic digestion products are routinely probed. Protein ID is also available on our new finnegan vMALDI ion trap mass spectrometer.
ESI-MS: Using our newly acquired Micromass API-US Q-TOF, we are able to pursue numerous applications related to MS, LC/MS, LC/MS/MS, as well as protein ID, using our dual-processor off-line Protein-Lynx server package. Applications include: spectra of proteins and small molecules, phospho-peptide analysis, protein identification, protein folding studies, and protein-protein interactions. Please consult with Steven Seeholzer for details.
Proteomics: By combining the techniques of multidimensional LC and fractionation using the SELDI with mass spectrometry, we are able to offer a full suite or services focused on meeting all of your proteomic needs. Services include in-gel digestions, reversed phase HPLC, 2D-LC (on our new beckman PF-2D), PMF Analysis and other mass spectrometry experiments. We are implementing an automated proteomic fractionation method to allow for precise expression difference mapping (EDM) analysis. A full suite of proteases are routinely stocked in the facility.
Structural Biology: The PCF has a state-of-the-art Jasco 810 Circular Dichroism CD with a thermal unit and auto-titrator. The instrument is also able to do steady- state fluorescence measurements. Additionally, we are working with Dr. Susan Wherli of the NMR core to assist in the characterization of proteins by NMR. Whether you might be interested in solving the structure of your protein in solution or characterizing its dynamic behavior, there are many experiments that we can assist with.
Biophysical methods for Molecular Interaction: Physical characterization of protein, protein interactions or protein small molecule interactions can be probed using a variety of in-house methods including analytical ultracentrifugation (AUC), Circular Dichroism, fluorescence, Biacore (SPR), ITC, and NMR. Consult with Steven Seeholzer if you are interested in pursuing studies involving these techniques.
Protein-Protein Interactions: Given the level of importance that protein interactions play at all levels of biochemical and cellular pathways, it is necessary to have the tools available to identify prominent partners. We are currently able to assist with co-immunoprecipitation, crosslinking, pull-down assays, far-western analysis, and protein microarrays (antibody, enzyme, library of ORF’s etc.).
The CHOP Protein Core Facility operates on a fee-for-service basis. We are not funded by research grants and therefore depend on service fees to effectively run our operation. If you feel that you have a significant amount of work that needs to be carried out, we suggest budgeting for this in your grants. Additionally, if you feel that you have a significantly large amount of samples, we will do our best to work out a mutually reasonable arrangement.
A detailed price list is now available for all services. CLICK HERE.