A method of washing an array of pipette tips with residual biological material, the method comprising: providing a dispensing jet system including the array of pipette tips; running a flush cycle by: lowering the array of pipette tips into a wash basin comprising an array of flush ports; and generating a vacuum such that the residual biological material in the array of pipette tips is evacuated through the array of flush ports; and running a wash cycle by: raising the array of pipette tips from the wash basin; filling the wash basin with a primary wash fluid; lowering the array of pipette tips into the wash basin; using a dispensing pipette piston cycle of the dispensing jet system to aspirate and dispense the primary wash fluid in the array of pipette tips; and generating a vacuum such that the primary wash fluid in the array of pipette tips and the wash basin is evacuated through the array of flush ports, characterised in that the wash basin further comprises a plurality of fingers configured to form an undulating surface which reduces surface area on which the primary wash fluid can sit, allowing effective evacuation of the primary wash fluid through the array of flush ports. providing a dispensing jet system including the array of pipette tips; running a flush cycle by: lowering the array of pipette tips into a wash basin comprising an array of flush ports; and generating a vacuum such that the residual biological material in the array of pipette tips is evacuated through the array of flush ports; and lowering the array of pipette tips into a wash basin comprising an array of flush ports; and generating a vacuum such that the residual biological material in the array of pipette tips is evacuated through the array of flush ports; and running a wash cycle by: raising the array of pipette tips from the wash basin; filling the wash basin with a primary wash fluid; lowering the array of pipette tips into the wash basin; using a dispensing pipette piston cycle of the dispensing jet system to aspirate and dispense the primary wash fluid in the array of pipette tips; and generating a vacuum such that the primary wash fluid in the array of pipette tips and the wash basin is evacuated through the array of flush ports, characterised in that the wash basin further comprises a plurality of fingers configured to form an undulating surface which reduces surface area on which the primary wash fluid can sit, allowing effective evacuation of the primary wash fluid through the array of flush ports. raising the array of pipette tips from the wash basin; filling the wash basin with a primary wash fluid; lowering the array of pipette tips into the wash basin; using a dispensing pipette piston cycle of the dispensing jet system to aspirate and dispense the primary wash fluid in the array of pipette tips; and generating a vacuum such that the primary wash fluid in the array of pipette tips and the wash basin is evacuated through the array of flush ports, characterised in that the wash basin further comprises a plurality of fingers configured to form an undulating surface which reduces surface area on which the primary wash fluid can sit, allowing effective evacuation of the primary wash fluid through the array of flush ports.