Figure 3.

In iliac crest-vacuum aspiration, the geometry of an aspiration syringe influences the proportion of MSCs in the aspirate. The pressure required to retrieve the mesenchymal cells is exerted at the tip of the needle and is defined by the formula: pressure (P) = force (F)/area (A), whereby the force used to create a vacuum is created by withdrawing the plunger of the syringe. This force remains relatively constant. Narrow, long syringes are, therefore, advantageous when harvesting MSCs using bone marrow aspiration.