Where diluent and reaction-reagent metering occurs in the instrument
Add diluent and assay-required lysing reagent at specified doses, checking actual sample/reagent ratios at the reaction site separately. For sheath-flow detection, define that branch's supply flow, pressure and stability separately; sheath supply is not equivalent to a single dilution dispense.
Include delivery errors, shared residue and mixing in ratio validation. Equal commanded volumes mean equal settings only; they do not replace measurement of received volume and detection results.
Product responsibilities in this operation
Syringe drive and valve positions jointly organize aspiration, holding and dispensing. Record working volume, remaining inventory and replenishment timing according to the sequence.
For this operation, confirm: Whole-blood aliquot; diluent and method-required lysing reagent; each delivered volume; addition order; reaction vessel and mixing; separate sheath-flow requirements where applicable.
Organize the sequence by actual architecture
- List sample, diluent and assay-required reaction reagents separately, defining target dose, addition order and mixing location for each branch.
- Deliver through actual valve paths and metering configuration, measure each branch's received volume at the reaction site, and check mixing and actual ratio.
- For sheath-flow detection, treat sheath supply as a separate branch and evaluate actual flow, pressure and stability rather than reusing a single dilution-dispensing sequence.
- After bottle changes or standby, recheck the first metered dose and detection-supply recovery separately, then check channel blanks and assay results.
Define operating conditions for this task
| To define | Details |
|---|---|
| Actual operating conditions | Whole-blood aliquot; diluent and method-required lysing reagent; each delivered volume; addition order; reaction vessel and mixing; separate sheath-flow requirements where applicable |
| Acceptance target | Measure the sample, diluent and reaction reagent received in the actual reaction path separately. Verify their ratio after the specified mixing sequence, including the first additions after standby or a bottle change. |
| Fault localization | A small sample-volume error, incomplete reagent delivery or retained liquid can alter the dilution ratio. Inadequate mixing may leave a nonuniform aliquot even when the combined volume is correct. |
Further technical reading
Compare product configurations by the roles on this page
| Product | Configuration option | Conditions to verify |
|---|---|---|
| HLD rotary-valve syringe pump | Aspiration, holding and dispensing with a rotary valve | Check source/outlet valve positions, capacity budget and replenishment timing |
| HMD solenoid-valve syringe pump | Metered aspiration and dispensing with solenoid valves | Check open/closed and power-off states, working volume and replenishment cycle |
Validate operation results at the receiver
Measure the sample, diluent and reaction reagent received in the actual reaction path separately. Verify their ratio after the specified mixing sequence, including the first additions after standby or a bottle change.
Use actual whole-blood conditions to assess the resulting channel blank and method response. Where detection uses sheath flow, evaluate that branch independently for sustained flow, pressure and stability.
Locate abnormalities and restore the next operation
A small sample-volume error, incomplete reagent delivery or retained liquid can alter the dilution ratio. Inadequate mixing may leave a nonuniform aliquot even when the combined volume is correct.
Identify the affected aliquot and which additions are complete. Restore each source path and verify first-dose delivery, then prepare a new dilution or handle the incomplete mixture according to the method; do not replay all additions into an uncertain vessel.
Metered dilution and sheath-fluid flow serve different functions. A correct dilution ratio does not establish the operating conditions of a sheath-flow detector.