Sample Preparation

I.  Single Cell Suspensions:  Achieving a single cell suspension the goal for a perfect sample preparation.  One of the easiest tricks is to remove any large aggregates by filtration (typically through fine 30-50um nylon mesh).  To minimize sample loss, use the techniques described below:


The following tools are required (sterilize as necessary):

  1. 1 syringe sufficient to hold your sample and one additional mL (retain cap).
  2. 1 Luer-Lock needle (typically 18 guage)
  3. 1 15mm x 15mm piece of nylon mesh (with a 30-50um mesh)
  4. 1 razor blade

The next step is to aspirate the sample up through the syringe needle such that your sample is loaded along with at least 1.0mL of air as a void volume.


aspirate sample Once the sample has been aspirated along with the 1.0mL of void volume, carefully dispose of the needle.  Maintain the syringe in an upright position so that the void bubble remains at the tip of the syringe.  


The next step is to sandwich the piece of nylon mesh over the tip of the syringe using the original syringe tip.  The idea is to use the tip to hold the filter mesh in place.  Once the tip is in place, carefully cut off the first few mm of the tip.  This will allow a hole for the filtered sample to pass through.  Additionally, take care to maintain the void bubble towards the tip so no sample is accidentally lost during this step.


At this point you need to invert the needle so the void bubble rises to the plunger.  Now the sample is ready to be passed through the filter mesh and the void bubble should ensure no sample remains in the syringe.




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