Residual particles and salt crystals in the nanopore adversely affect performance, proper cleaning will alleviate this risk.
At the end of an experiment it is critical to wash out the pore before removal of the nanopore from the TRPS instrument.
Exoid users will be guided through these steps during and after measurements, qNano users will need to follow these steps manually.
Cleaning the Nanopore Between Samples
- Ensure the nanopore is stretched to at least 47 mm.
- Remove the pressure nozzle.
- Remove the sample from the upper fluid cell with a pipette.
- Wash the upper fluid cell using measurement electrolyte by reverse pipetting three times, then load 35 µL of fresh measurement electrolyte into the upper fluid cell ensuring no bubbles are present.
- Apply maximum pressure for at least 30 seconds until there are fewer than 10 blockades per minute measured, you may need to wash the upper fluid cell out with measurement electrolyte multiple times to achieve this. If after multiple washes a blockade rate of less than 10 per minute cannot be achieved, remove the fluid from both upper and lower fluid cells, de-stretch and remove the nanopore. Rinse the nanopore and upper fluid cell with DI water and dry. If cleaning the nanopore for storage, proceed to the next instructions, otherwise repeat step 4-5 until fewer than 10 blockades per minute are observed before continuing to the next measurement.
Cleaning the Nanopore for Storage
- Once the nanopore has been cleaned with ME to remove sample or calibration particles, the pore should be flushed with DI water for storage. Remove the upper fluid cell, wash with DI water and dry via tapping the upper fluid cell onto a tissue or using an air-gun. Remove the nanopore, rinse with DI water and dry with a lint-free tissue. Remove the fluid from the lower fluid cell and wipe dry gently. Re-set up the nanopore using DI water in the upper and lower fluid cells and apply maximum pressure until the current drops to <5 nA. The DI water in the fluid cells may need to be changed multiple times to achieve this.
- Once completed, remove the fluid from the fluid cells.
- Remove the nanopore, rinse with DI water and dry with a lint-free tissue. Rinse the upper and lower fluid cells with DI water and dry, and make sure the inside of the shielding cap is also clean and dry.
- Store the nanopore back in its clean, sealed bag.
Thorough cleaning and proper handling of the nanopore is paramount in increasing the probability of successful re-use of the nanopore. It is good practice to keep a record of the type of sample that a nanopore has been exposed to.
Nanopores that have been exposed to virus samples will need to be decontaminated with 70% ethanol.