Bio-Rad EXQuest Spot Cutter - Manual (Page 9)

INTRODUCTION
1-5
• Membrane Cutting Head. The membrane cutting head is an optional accessory that is used for
cutting PVDF and nitrocellulose membranes. As downward motion is applied to the cutting head, the
mechanism causes the tip to twist and cut the membrane. For best cutting efficiency, a sharp tip
should be used. If the tip becomes dull or damaged it should be replaced. The membrane cutting tip
must contact water to efficiently eject membrane plugs. Therefore, microplate wells and tubes must
be filled with enough water to cover the end of the cutting tip. Low water level in the wells will result
in membrane plugs missing the well or being delivered to waste.
• Caution – the membrane cutting tips are sharp. The membrane tips should only be used to cut
PVDF and nitrocellulose membranes in order to maintain their sharpness. New membrane cutting
tips may be purchased from Bio-Rad (see Accessories, Section 9).
1.2.5 Fluidics System
The fluidics system consists of water and waste reservoirs, pumps and sensors. It has two major functions:
gel spot pickup and delivery; and waste removal.
• Syringe Pump. The syringe pump delivers water used for gel plug delivery, gel and membrane
hydration and gel tip washing. It is also used to create a weak vacuum for loading gel plugs into the
cutting tip.
• Water reservoir and level sensor. This reservoir holds cross-contamination water used for gel plug
delivery, gel and membrane hydration and gel tip washing. The level sensor “alerts the operator that
the water level is low” and stops the cut run.
• Waste reservoir and level sensor. This reservoir holds waste water generated from washing gel tips.
The level sensor prevents experiments from being run until the waste is emptied.
• Waste pump. The waste pump is used to pump waste from the wash station waste basin (see
Figure 1-6) to the waste reservoir.
• Waste filter. The filter is used to prevent gel and membrane debris from clogging the waste pump.
This filter should be checked and cleaned periodically (see Maintenance Section 10.1)
1.2.6 Wash Station
The wash station is used to reduce cross contamination between cuts. After each cut, the cutting head
moves to a microplate well, deposits the gel or membrane plug, and then goes to either the gel tip wash
station or the membrane tip wash station.
Figure 1-6. Wash station.