How do I avoid contamination?

Some batches of vials and tubes are not completely free of micron and nano-sized particles; this is particularly common in low grade, cheaper brands. Izon uses tubes and vials from Axygen. When similar samples were prepared in tubes from two different suppliers. Large populations of contaminants were present in one of the tubes. 
 

Prior to the use of a new batch of consumables, Izon recommends completing the following testing protocol: 

1. Prepare a test sample for analysis using the new consumables. This test sample should be of filtered blank electrolyte that is prepared by following typical particle preparation procedures. For example, if a sample diluted in electrolyte is typically sonicated or vortexed, then the electrolyte should be sonicated and vortexed. DO NOT add any particles into this test sample. 
2. Select a nanopore that covers a size range for which measurements will be made using the instrument. 
3. Set up the nanopore on the instrument using the test sample and establish a baseline current at the following settings: Applied stretch of 47 mm and applied voltage required to obtain a current of 100 nA.
4. Apply a pressure of 5 mbar.
5. Reset the count. If a number of blockades are present in the size histogram, this indicates the presence of potentially significant contamination.
6. Repeat Steps 2-4 for any additional nanopore size ranges that will be used with the instrument