Pumps, valves, probes, fittings, tubing and sensing components for precise sample preparation, reagent handling and instrument fluidics.
Sampling Probes for Aspiration and Liquid Delivery
Application guide · Sampling probes
A sampling probe must reach the valid liquid region, acquire the required aliquot and leave the source without clot pickup, wall sealing, external droplets or excessive carryover. Probe geometry, Z motion and pump program are one sampling method.
Engineering example: if a method needs 5 μL but the minimum residual specimen must remain 20 μL above a conical bottom, the aspiration height and tube tolerances may limit access before pump capacity does. A smaller command cannot recover liquid that the tip cannot safely reach.[1][2]
01Define the liquid, receiver and complete duty before selecting the component
Translate the analytical task into an engineering duty
Use case
Inputs to define
Decision supported
Serum/plasma aspiration
Minimum available volume, fibrin/clot risk and tube type
Set tip geometry, level strategy and aspiration speed
Urine or low-viscosity sample
Sediment and mixing requirement
Define pre-mix and sampling height
Reaction-cup transfer
Receiving geometry and liquid-release mode
Avoid wall retention and splash
02Calculate the working point and the margin the instrument really needs
Calculations to complete before prototype selection
Quantity
How to define it
Why it matters
Immersion window
liquid height range − bottom/wall clearance
Defines valid Z positions
Required source volume
aliquot + overdraw + protected residual
Sets minimum sample claim
External wash coverage
immersed/contact length + margin
Sets wash-station geometry
Use minimum, routine and maximum conditions rather than one nominal point. Include the first cycle after priming or idle, the lowest source level, the highest expected restriction and the actual receiving geometry. A nominal capacity, free-flow value or theoretical command increment is not an acceptance result.
03Map the task to a FOREACH configuration and the rest of the fluid path
04Program the full liquid cycle, including prime, wash and recovery
Identify vessel→Approach or detect surface→Immerse to taught depth→Aspirate slowly and dwell→Withdraw without droplet loss→Dispense, then wash inside and outside
A complete method cycle is more than the active delivery step
The exact physical order and parallel actions depend on the instrument. Retain each state in the control and verification plan.
Record valve states, motion, dwell, sensor windows and rejected recovery cycles. This makes throughput and liquid consumption auditable and prevents a fast component movement from being reported as the complete analyzer cycle.
05Design abnormal-state diagnosis before the fault occurs
Observed result, likely mechanism and useful next action
Observed condition
Likely mechanism
Engineering response
No/partial sample
Low level, clot or tip sealing on bottom
Reject result and inspect height/pressure evidence
Carryover
Incomplete internal/external wash
Locate sample-contact surface and qualify wash
Sample composition shifts
Sediment, evaporation or system-fluid intrusion
Control mixing, timing and sample segment
The controller should distinguish a recoverable event from a result-invalidating event. A retry is useful only after the original cause has been removed and the liquid path has returned to a verified state.
06Accept performance where the liquid is actually used
Minimum qualification plan for the integrated channel
Result
Where or how to measure
Acceptance question
Sample delivery
Tracer/analyte at reaction vessel
Correct effective sample, not volume alone
Minimum source volume
Worst tube and level tolerance
Aliquot delivered without bottom contact
Carryover
Worst high-to-low sample sequence
Meets assay-specific limit
Test the exact liquid and complete wetted path at minimum, routine and maximum conditions.
Separate first-cycle, steady-state and post-idle results; do not average away recovery behavior.
Challenge the relevant fault and confirm the controller prevents an invalid result from being accepted.
Retain the configuration, software sequence, consumables and receiving-position result together as the qualification record.
