Locate the task in the fluid path first
Arrows indicate task relationships, not that every component is connected in series in one tube. Check valve positions, pump wetted boundaries and operating states for each branch.
Set aspiration speed, immersion depth, air gaps, dwell and dispensing mode for the target liquid. For multiple dispenses from one aspiration, budget first and last doses and retained volume. Check each channel and receiving position separately.
Common product roles and application guides
| Product category | Role in this instrument |
|---|---|
| Piston pump | Discrete metering for suitable fixed-probe configurations |
| Syringe pump | Liquid-displacement drive for fixed probes |
| Air-displacement pipetting pump | Air displacement with disposable tips |
| Sampling Probes | Fixed-probe interface with the container |
| Bubble and pressure detection | Signals the controller can associate with pipetting stages |
| Tubing and fittings | Fixed-path sealing and shared volume |
Operating requirements differ by step
| Stage | Task category | Operating conditions to define |
|---|---|---|
| Single transfers: establish liquid type and sealing | Pipetting and receiving | Disposable-tip or fixed-probe architecture, sealing, working volume, liquid class, immersion position and dispensing action |
| Multiple dispensing: calculate usable volume per aspiration cycle | Dispensing operating conditions | Dose per operation, total cycle volume, replenishment/bottle-change interval, backpressure and receiving geometry |
| Washing or tip replacement: define contamination controls for the architecture | Return to service after washing or tip changes | Fixed-probe or tip architecture, wetted surfaces, tip-change rules and contamination targets |
Single transfers: establish liquid type and sealing
Viscosity, volatility and surface tension can alter air-displacement performance. Calibrate with the actual tips and containers, then assess low source volumes and high-speed operation.
Multiple dispensing: calculate usable volume per aspiration cycle
Nominal capacity minus retained volume determines the usable dispensing range. Record every dose, comparing first, middle and last doses and the first dose after replenishment, rather than measuring the average alone.
Washing or tip replacement: define contamination controls for the architecture
For reusable probes, manage internal and external wetted surfaces. For disposable tips, manage pickup, changes and disposal. Use sample sequences and blanks to determine whether the strategy is adequate.
Explore configurations through product application guides
Validate the complete cycle through application results
Measure delivery with actual liquids, tips and well positions, including idle periods, refills and multiple dispensing.
| Step to validate | Measurements or observations | Priority troubleshooting checks |
|---|---|---|
| Single transfers: establish liquid type and sealing | Measure delivered volume in the actual receiving container, including low source levels, tip changes or probe washing, and carryover between samples. | Seal leaks, air aspiration, retained droplets or incorrect immersion can alter delivery. |
| Multiple dispensing: calculate usable volume per aspiration cycle | Use actual media to check first, middle and last doses and delivery after bottle changes; confirm received volume and timing rather than substituting commanded steps for volume | Empty sources, bubbles, nozzle droplets and backpressure changes affect first or last doses |
| Washing or tip replacement: define contamination controls for the architecture | For fixed needles, check washing and blank recovery. For tip-based architectures, check pickup sealing, tip replacement and contamination across sample sequences. | Insufficient wash coverage, a missed tip change or a failed seal may affect the next sample |
Nominal capacity and volume per step do not establish the minimum reliable pipetting volume. Disposable tips and reusable probes require different cleaning strategies.
Common selection and recovery questions
Is nominal capacity equal to the total reagent volume available for one dispensing cycle?
Calculate air gaps, retained volume and each delivery from the actual working stroke and program, then set refill points. Validate received volume at the probe or tip outlet.
Can disposable tips eliminate cleaning validation?
Validate tip pickup sealing, changes and ejection against the consumable strategy, and check contamination across sample sequences. For fixed probes, evaluate internal and external washing and waste removal separately.