Dead volume is defined as the volume of solution that remains in the needle after an injection. To achieve a precise dispense the dead volume must be completely primed with sample by rapidly filling and dispensing until the air bubbles are flushed from the system. Once primed the dead volume does not contribute to the volume aspirated or dispensed by the syringe.
Calculating Needle Dead Volume
The dead volume and dimensions of the needle tubing are listed in the Gauge Index. The dead volume can be calculated by the equation (inner diameter/2)²(π)(needle length). Add this to the dead volume of the needle hub to get the needle’s total dead volume. For a Metal or Kel-F Luer Lock Needle connected to a Hamilton syringe add 10 µL, and for a Removable Needle there is no additional dead volume.