Protein Core Facility

Saint Louis University’s Protein Core is a shared-use core facility that supports expression, purification and analysis of reagent and preclinical proteins.

The core provides instrumentation and consultation for small to large protein production.

Current projects are concentrated on structural biology, process development of novel protein therapeutics and targeted proteomics. Capabilities of the lab include:

  • Bacterial fermentation and shake flask production
  • Expression screening and optimization
  • Protein analysis for quantity, purity and identity
  • Purification process development for scale-up, including protein therapeutics
  • Biophysical analysis of proteins for purity, solution molecular mass and protein-protein interactions
  • MALDI-QIT-TOF (Axima Resonance™) mass spectrometry for analysis of primary structure and post-translational modifications
    Protein mass spectrometry

Equipment

Available equipment includes shaking incubators, a 5 L fermentor, high-pressure cell disruptor, hollow fiber concentrator, Maxwell16™ magnetic bead purification system, AKTA™ Purifier chromatograph, analytical ultracentrifuge, analytical HPLC, and MALDI-QIT-TOF mass spectrometer.

Analytical Services

Protein Identification

Isolated gel band or purified protein is digested with suitable protease after reduction/alkylation. Peptide MS and MS/MS analysis with MALDI-QIT-TOF and Mascot database search.

Protein Identification: Instrument Only

Sample preparation, data collection and analysis are carried out by a SLU researcher after instrument training.

Protein Expression Analysis

For optimization of protein expression or purification conditions, or for the screening of constructs and host-vector combinations. Small scale (5 to 100 mL) bacterial cultures for one to six samples are analyzed by induction, lysis and SDS-PAGE (Coomassie) of soluble and pellet fractions.

Protein-Soluble Recovery by Affinity Tag Bind/Release

For confirmation of soluble protein by affinity capture and elution under non-denaturing conditions. Small scale bacterial cultures for one to four samples are analyzed by induction, lysis, affinity bind/release and SDS-PAGE (Coomassie) of soluble, unbound and eluted fractions.

Preparative Services

Shake Flask Bacteria Induction, 1 to 6 Liters
Production of recombinant protein in shake flasks for later purification.
High Density Bacteria Fermentation, 3 to 5 Liters

Production of recombinant protein using a New Brunswick fermentor according to established protocol for high-density bacterial culture.

Protein Chromatography, Preparative

Protein chromatography using 1 to 50 ml column. Cell lysis, clarification, chromatography and SDS-PAGE analysis (Coomassie) are included. This is typically carried out using the AKTA Purifier instrument but batch bind/release protocol available.

Protein Chromatography, Instrument Only

Preparative protein chromatography using 1 to 50 ml columns. Cell lysis, clarification, chromatography and SDS-PAGE analysis (Coomassie) are carried out by a SLU researcher after training.

Dialysis or Buffer Exchange

Places protein product in a suitable buffer for storage or stability analysis. Uses G-25 column or dialysis tubing for up to six small volume samples.

Protein Concentration

Protein solution for up to six small volume samples is concentrated using an ultrafiltration membrane spin concentrator. Quantification of final protein by absorbance or Bradford assay.

Concentration/Diafiltration Using Hollow Fiber

Applicable to larger volume protein samples of 1 to 50 L. The concentration is combined with buffer exchange using a hollow fiber ultrafiltration cartridge.


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Fees 

Analytical Services  SLU investigators External investigators
Protein identification $396 $481
Protein identification, instrument $201 N/A
Protein expression analysis $509 $618
Protein-soluble recovery (affinity tag) $1,036 $1,258
 

 

Preparative Services  SLU investigators External investigators
Shake flask bacteria induction, 1 to 6 liters $243 $295
HD bacteria fermentation, 3 to 5 liters $496 $603
Protein chromatography, preparative $419 $509
Protein chromatography, instrument $126 N/A
Dialysis or buffer exchange $130 $158
Protein concentration $90 $110
Concentration/diafiltration, hollow fiber $680 $826