askvity

How to Store Plasmids on Filter Paper?

Published in Plasmid Storage 3 mins read

To store plasmids on filter paper, deposit the plasmid DNA onto the filter paper and then store it in a refrigerator at 4 degrees Celsius.

Here's a slightly more detailed breakdown of why and how:

  • Why use filter paper? Filter paper provides a convenient and relatively stable matrix for long-term storage of plasmid DNA. It allows for easy retrieval by dissolving the DNA back into a buffer.

  • How to do it:

    1. Prepare the plasmid DNA: Ensure your plasmid DNA is relatively pure and in a suitable buffer (e.g., TE buffer).
    2. Apply to filter paper: Carefully pipette a small volume of your plasmid DNA solution onto a clean piece of filter paper (e.g., Whatman paper). A defined spot helps with resuspension later. The volume will depend on your concentration, but typically a few microliters are sufficient.
    3. Allow to dry completely: Let the filter paper air dry completely at room temperature. This is crucial to prevent degradation.
    4. Storage: Store the dried filter paper in a sealed container (e.g., a small plastic bag or tube) in a refrigerator (4°C). Avoid humid environments and locations with fluctuating temperatures. A desiccant packet can be added for extra protection.

  • Retrieval:

    1. Cut out the DNA spot: Using clean scissors or a scalpel, carefully cut out the area of the filter paper where the DNA was applied.
    2. Resuspend the DNA: Place the filter paper piece into a microcentrifuge tube and add an appropriate volume of buffer (e.g., TE buffer, sterile water). The volume will depend on the amount of DNA you originally applied. Start with a small volume (e.g., 20-50 μL) and adjust as needed.
    3. Incubate: Incubate the tube at room temperature or at 50-65°C for 10-30 minutes to allow the DNA to dissolve off the filter paper. Vortex occasionally to aid resuspension.
    4. Spin down: Briefly centrifuge the tube to pellet any remaining filter paper debris.
    5. Use the supernatant: Carefully transfer the supernatant (containing the resuspended DNA) to a new tube and use it for downstream applications, such as transformation or PCR.

  • Important Considerations:

    • Purity: The purity of your plasmid DNA is important. Contaminants can affect long-term stability.
    • Storage Temperature: While Addgene recommends 4°C, some labs may opt for -20°C for even longer-term storage.
    • DNA Concentration: A reasonable DNA concentration is important for successful recovery.

Related Articles