Immunoaffinity Cartridges for Mycotoxins: Common Questions and Answers

Mycotoxin Immunoaffinity Cartridges—These cartridges adsorb mycotoxins based on the specific interaction between antigens and antibodies. For first-time users, there are often many questions. The most frequently asked questions include:

• 'How do I use the immunoaffinity cartridge?'
• 'Should the preservative solution in the cartridge be retained when passing the sample through?'
• 'Will it affect the results if I don’t add PBS buffer?'
• 'Will directly using the cartridge without preparation affect recovery?'
• 'I forgot to remove the cartridge and left it outside for a few days. Is it still usable?'

Additionally, some experienced users often ask:

• 'Why is the recovery rate so low?'

In response to various customer inquiries about the correct use of immunoaffinity cartridges and points of attention, we have summarized the key aspects to help you understand the process:

Usage Instructions

1. Column Installation and Preparation

Remove the immunoaffinity cartridge from storage conditions and allow it to equilibrate to room temperature for at least 30 minutes. Connect the sample injection syringe to the immunoaffinity cartridge, then mount it onto a pump flow operation rack or solid-phase extraction device. Ensure the cartridge is installed correctly, and check its seal and integrity.

2. Sample Preparation

Choose an appropriate buffer solution for sample dilution based on the properties of the substance to be purified. Before injecting the sample solution into the affinity cartridge, perform necessary pretreatment steps, such as filtration or centrifugation, to remove impurities that may interfere with the analysis. Additionally, control the sample's pH and ionic strength to facilitate the binding of target molecules.

3. Sample Loading

Before loading, discard the preservative solution. During sample loading, control the flow rate to prevent the loss of target molecules or nonspecific adsorption due to excessively fast or slow flow.

4. Washing

Use an appropriate amount of wash buffer to rinse the cartridge, removing unbound impurities. This step is crucial for enhancing the purity of the purified product.

5. Elution

Employ an appropriate elution buffer, such as one that alters the pH or increases salt concentration, to disrupt the non-covalent bonds between the antigen and antibody, thereby releasing the target substance. Collect the eluate to obtain the purified product.

Precautions
(The following 7 points can all affect the recovery rate!)

1. Avoid Dry Columns: Immunoaffinity cartridges should not be dried, as this can damage antibody activity. The column should always remain moist during use. If the preservative solution inside the cartridge has already dried out when you take it, it is not recommended to use it.

2. Temperature Control: Immunoaffinity cartridges should be stored at 2°C–8°C. All operations should be performed at room temperature unless otherwise specified. Excessively high or low temperatures can affect the antigen-antibody binding efficiency.

3. Prevent Blockage: Samples should be filtered or centrifuged beforehand to remove any particles that could clog the cartridge.

4. Control Flow Rate: The recommended flow rate is between 0.5 mL/min to 2 mL/min. Avoid excessive or insufficient flow rates to ensure full interaction between the sample and the antibodies.

5. Solution Requirements for Immunoaffinity Cartridges:

   • The organic phase concentration should generally not exceed 10% for methanol and 20% for acetonitrile. The pH of the wash or loading solution should be between 6 and 8; otherwise, it may affect the recovery rate.
   • It is recommended to use 2 mL of 2% acetic acid in methanol for elution. If using pure methanol, elution may be incomplete, resulting in a lower recovery rate.
   • Depending on the target compound, elution conditions may need adjustment, such as pH or salt concentration, to achieve optimal purification.

6. Do Not Use Expired Cartridges: Expired cartridges should not be used, and used cartridges should be disposed of properly to avoid environmental contamination.

7. Follow the Manufacturer’s Instructions: Strictly adhere to the instructions provided by the manufacturer, particularly regarding buffer selection and elution conditions. If any issues arise, promptly contact the manufacturer’s technical support.