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
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.
Sample preparation, data collection and analysis are carried out by a SLU researcher after instrument training.
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.
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
Production of recombinant protein using a New Brunswick fermentor according to established protocol for high-density bacterial culture.
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.
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.
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 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.
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 |