Working with Small Sample Volumes or Low Start Cell Numbers Using the Purple EasySep™ and EasyPlate™ EasySep™ Platforms

When performing cell separation procedures, it is sometimes necessary to work with small sample volumes or low cell numbers. In these situations, there are several tips for improving cell recovery and overall performance of the isolation procedure.

Our EasyPlate™ EasySep™ Magnet (Catalog #18102) is designed for processing a small number of cells (for the minimum and maximum number of cells per well, please refer to the EasyPlate™ Product Information Sheet (PIS) of the kit you are using), and serves as an excellent alternative to the handheld Purple EasySep™ Magnet (Catalog #18000) when performing small volume or low cell number separations. The EasyPlate™ magnet is designed to hold a round bottom, non-tissue culture-treated 96-well plate (e.g. Costar, Catalog #3788). The EasyPlate™ magnet is compatible with selected EasySep™ Enrichment Kits (refer to the webpage of the kit of interest).

After the magnetic separation step, carefully pour off the supernatant in one slow continuous motion. Leave the magnet and tube in the inverted position for 2 - 3 seconds, then return to the upright position. Do not shake or blot off any drops that may remain hanging from the mouth of the tube. Please view this video of the proper pour-off technique.

For an overview on using the EasyPlate™ magnet please see this brief technical video. As well, please refer to these additional tips for successful isolation of enriched cells using the EasyPlate™ EasySep™ Magnet (Catalog #18102):

  1. Ensure the 96-well plate sits securely on the EasyPlate™ magnet when removing the supernatant containing the enriched cells.
  2. Carefully tilt the plate and magnet together at a 45° angle when removing the supernatant to avoid disturbance of the particles and unwanted cells at the bottom of the well.
  3. Carefully pipette the enriched cell suspension from each well into a new 96-well plate. Do not pour. The magnetically labeled unwanted cells will remain bound to the bottom of the original well, held by the magnetic field of the EasyPlate™ magnet. The negatively selected, enriched cells in the new 96-well plate are now ready for use.

When using the Purple EasySep™ Magnet (Catalog #18000) with small volumes or low cell numbers, the following recommendations can help to make your cell separation procedure more successful:

  1. Always be sure to know the minimum number of total nucleated cells that can be reliably processed with the particular EasySep™ kit (refer to PIS for minimum capacity). However, if starting with less than the recommended minimum volume of cells, top up the initial sample with the recommended buffer to the minimum volume as stated in the PIS.
  2. If starting with frozen cells, be sure to add DNAse I (Catalog #07900) to your sample.
  3. After the magnetic separation step, carefully pour off the supernatant in one slow continuous motion. Leave the magnet and tube in the inverted position for 2 - 3 seconds, then return to the upright position. Do not shake or blot off any drops that may remain hanging from the mouth of the tube. Please view this video of the proper pour-off technique.

NOTE: It is highly recommended to analyze a small amount of cells from the starting (pre-separation) fraction by FACS to determine the % purity of your cells of interest in the start sample population. This information is required for calculating cell recovery post-separation. Find more details on assessing your starting sample and calculating recovery.

Please contact techsupport@stemcell.com for further information on our EasyPlate™ EasySep™ Magnet protocols and compatible EasySep™ kits.