Protein Precipitation/ Peptide Purification
Solid Phase Extraction (SPE) is one of the most common methods for preparing samples to be analyzed by Mass spectrometry. The common workflow runs samples down through a syringe cartridge with absorbents (often silica or carbon-based) several times and the size for these cartridges is mostly 1ml, 3ml or 6ml. Although this cartridge-based method works perfectly fine with samples in large volumes, it can create recovery issues when dealing with small volumes (roughly 1ml in total) since there will not be enough samples to be thoroughly eluted into collection vials. Research on metabolomics or peptides often investigates various human samples in high throughput and thus comes in small volume. Using an ordinary cartridge in these applications not only introduces a lower recovery rate but is also inefficient since these loaded syringes take up space and only a few can be run at the same time.
A filtration plate has been developed to serve this purpose and there are multiple types available in the current market, each suitable for a corresponding elute (from peptides to metabolites etc.). They have the exact layout/dimension as a standard 96-well plate which supports a high-throughput (96 samples at a time) but low-volume (less than 1ml) extraction. These plates are easy to use as well – one can either apply a positive pressure (for example: Thermo’s SOLAµ™ SPE Plates) or a vacuum manifold (for example Phenomenex’s Impact™ Protein Precipitation Plates) to push eluents through the filter and the whole workflow looks almost identical to the ones using ordinary carbon cartridges.
One of our clients from the hospital core lab has been using Phenomenex’s Impact™ Protein Precipitation Plates for their metabolomics research and with the assistance of VERSA 1100 SPE, to automatically prepare patient samples for GC/MS analysis monthly. The VERSA 1100 SPE Workstation offers flexibility in sample throughput by accommodating 1, 3, and 6 mL cartridges, and 96-well SPE cartridge plate formats. With 15 deck positions and a variety of dedicated modules, including positive and negative pressure applicators, a nitrogen dryer, and a shaker-heater, the system’s versatility can be extended to include sample extraction as well as derivatization and reconstitution for further analysis.
Thermo’s SOLAµ™ SPE Plate
Phenomenex’s Impact™ Protein Precipitation Plates
Applications – VERSA Automated Solid Phase Extraction Systems
- Food Safety
- Vitamin D from Blood/Serum Samples
- Drugs of Abuse in Forensic Analysis
- Environment Health
- Compounds for Drug Discovery
- Iso-flavonoids from Urine Samples
- Aflatoxins from Seafood Products
- Metabolite Extraction
- Growth Promoters in Blood
- Semi-volatile or Non-volatile Analytes
- Protein Precipitation
Specifications | Versa1100 | Versa2100 |
| Deck Capacity | 15 | 24 Deck Positions |
| Pipetting Head (Single Channel Function, Disposable Tip) | 4 or 8-channel | 4 Channel Pipette (1000uL) |
| ReagentDrop | up to 8 | 5 Channel Reagent Drop (bulk dispensing) |
| Supported Cartridges | 24 test tubes/vials and 96 deep well plates | SPE cartridge compatible |
| Gripper / Plate Transporter | Gripper | Gripper |
| Reagent Block / Flat Plate Coolers | Optional | Optional |
| Nitrogen Dryer | 24 or 96 channels | 24 or 96 channels |
| Shaker-Heater (2400rpm, RT to 90°C) | Optional | Optional / 4-in-1 Shaker for 4x Sample Tube Racks 4×6 |
| Liquid Level Sensing | Optional | NA |
| HEPA/UV/LED Enclosure | Included | Included |
| Sonicated Wash Station | NA | Optional |
| Width x Depth x Height (cm) | 99 x 75 x 90 | 120 x 84 x 200 (Including Bench) |
| Weight (kg) | 162 | ~500 |
What is the throughput?
It can be configured for 24-sample or 96-well format depending on instrument channels (4 or 8-channel head) – actual throughput time will depend on the specific procedure and steps involved.
Does the instrument come with its own nitrogen supply or does it use the lab’s?
The workstation’s nitrogen dryer has to be connected to the overall lab’s nitrogen supply for any drying step.
What liquids are compatible?
a. For ReagentDrop – most organic solvents are compatible – avoid concentrated aqueous solutions (salting out could clog the tubing) and concentrated acids or bases (can degrade metal components).
b. For pipetting and solutions on deck – avoid very volatile solvents and any concentrated acids or bases (fumes can degrade instrument components).
What is the sample handling volume?
a. Pipette maximum aspiration/dispensing volume is 1000uL.
b. Samples handling is around 10-15 mL.
Can the samples and solvent be kept cool?
Yes, we have cooler/heater flat plates that can bring down the temperature to 4 oC.
What sample sizes/consumables are compatible?
We have custom fabrication/3D printing abilities to meet whatever your needs.
What if my solvent is not compatible with polypropylene pipette tips?
We can offer a steel-pin system (4 or 8-channel, up to 1000 uL) system.
Is barcode tracking available?
Barcode tracking is optional.
What column sizes are compatible with the VERSA 1100 SPE?
Our system can fit 1 mL, 3 mL, and 6 mL SPE cartridges which would then use a positive pressure module, as well as 96-well SPE extraction plates which would use a vacuum system instead of a positive pressure modulator.
Difference between a vacuum system and positive pressure module?
A positive pressure module will be used for conditioning, washing and elution if the samples are processed in cartridge columns. A vacuum system is used if the samples are processed in a 96-well plate.