On a system-liquid instrument the syringe, or dilutor, is the muscle behind every transfer, and its size is a decision you live with. No liquid class can deliver resolution the fluidic path does not physically allow, so the pump you specify sets the ceiling on what any class built for that instrument can achieve. It is worth understanding before you buy, not after.
The syringe trade-off
A syringe moves its full volume over a fixed number of motor steps, so its size trades range against resolution. A small syringe resolves tiny volumes finely but tops out at a low maximum, while a large syringe reaches big volumes but cannot finely resolve a microliter. Size the syringe to the volumes you actually dispense most, and accept that a very wide working range may need a different syringe rather than one heroic class.
The rest of the path matters too
- Valves and tubing set dead volume and how quickly the path can prime, aspirate, and switch between system liquid and sample.
- Tubing compliance, its slight give under pressure, behaves a little like an unwanted air cushion, blunting the directness that a system-liquid path is chosen for.
- Vented tips let you aspirate from a closed source vessel without pulling a vacuum that starves the draw, which otherwise quietly short-fills every transfer.
- Pressure monitoring on the pump turns the path into a sensor for clots and empty wells, the same benefit monitored pipetting brings to air-displacement channels.
Specify the path around the work
The order that saves grief is to start from the liquids and volumes the lab runs, then choose a syringe and path that comfortably cover them, and only then develop classes. Trying to rescue a mismatched fluidic path with clever liquid-class tuning is how you end up fighting physics. The hardware sets the envelope; the class works within it.
No liquid class beats its fluidic path. Match the syringe and pump to your volume range first, and the classes get much easier to build.