In the field of biomedical research, peptides are an important type of bioactive molecules, and their purity and quality are crucial to drug development and therapeutic effects. However, inorganic salts and other impurities produced during the synthesis of peptides often reduce their purity, thereby affecting their biological activity and stability. To solve this problem, scientists have developed a variety of peptide desalting technologies. Among them, the peptide desalting workstation based on the Opentrons OT-2 pipetting workstation has become an indispensable tool in the development and production of peptide drugs with its advantages of high precision, automation and flexibility.

OT-2 peptide desalting workstation

1. Preparation work 1. Equipment preparation: Make sure that the OT-2 pipetting workstation is in good working condition, and check whether the pipette, temperature control module (if necessary), chromatography column (if gel filtration method is used) and other accessories are complete and Functions normally. 2. Reagent preparation: Prepare peptide solution, desalting buffer, eluent and other required reagents, and ensure that their quality and concentration meet experimental requirements. 3. Sample processing: Perform appropriate pretreatment of the peptide solution, such as dilution, pH adjustment, etc., to meet the requirements of the desalting process.

2. Desalting process 1. Pipetting operation (1) Aspirate the polypeptide solution: Use the high-precision pipette of OT-2 to suck the polypeptide solution out of the original container and prepare for desalting. (2) Distribute to desalting device: Distribute the absorbed peptide solution to a desalting device, such as a dialysis bag, chromatography column or specific desalting plate. 2. Selection of desalting method (1) Dialysis method: Place the polypeptide solution in a dialysis bag, and then place the dialysis bag into a container containing desalting buffer. Through dialysis, the peptide molecules will remain in the dialysis bag, while the small molecule salts will diffuse through the dialysis membrane into the buffer. (2) Gel filtration method: filter the polypeptide solution through a chromatography column. The gel particles in the chromatography column will be excluded based on the size of the molecules. The peptide molecules will be retained on the gel particles, while the small molecule salts will flow out with the eluent. (3) Electrophoresis method (less commonly used): Under the action of an electric field, polypeptide molecules will migrate according to their charge and molecular weight, thereby achieving separation from salts. However, electrophoresis is rarely used in peptide desalting because the operation is complex and the cost is high. 3. Automated control (1) Writing protocol: According to the desalting method and experimental requirements, use the software platform provided by Opentrons to write a customized desalting protocol. Details such as pipetting operations, temperature control settings, elution steps, etc. should be included in the protocol. (2) Execute the protocol: Upload the written protocol to the OT-2 pipetting workstation and start execution. OT-2 will automatically complete pipetting, temperature control, elution and other steps according to the instructions in the protocol.

3. Follow-up processing 1. Collect polypeptides: After desalting is completed, collect the polypeptide solution left in the dialysis bag, on the chromatography column or after electrophoresis according to the desalting method used. 2. Purity detection: Use appropriate methods (such as SDS-PAGE, HPLC, etc.) to detect the purity of the polypeptide to ensure that the desalting effect meets the experimental requirements. 3. Storage and use: Store the desalted peptide solution appropriately (such as freeze-drying, refrigeration, etc.) for subsequent experimental use.

4. Notes 1. Experimental conditions: Experimental conditions such as temperature and pH value should be strictly controlled during the desalting process to ensure the stability of the peptide and the desalting effect. 2. Reagent quality: The reagents used should have high purity and stability to avoid contaminating the polypeptide or affecting the desalting effect. 3. Equipment maintenance: Clean and maintain the OT-2 pipetting workstation regularly to ensure its long-term stable operation and accurate pipetting.

The peptide desalting workstation built on OT-2 can significantly improve the efficiency and quality of peptide desalting through automated pipetting, flexible selection of desalting methods and precise control of experimental conditions. At the same time, the workstation is also highly scalable and customizable to meet the requirements of different experimental needs and peptide types.

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