An assay that cannot run on your installed base is not a bargain, however strong its clinical data. Yet compatibility screening is routinely reduced to a checkbox on a supplier questionnaire, and incompatibilities surface months later as workarounds: adapters bought to bridge plate formats, a second analyser run at partial utilisation, or a validated method quietly confined to one instrument while the menu says otherwise. A structured compatibility review before shortlisting removes most of that risk.
Open, closed, and validated-open systems
Closed systems — cartridge and cassette platforms — bundle reagents, consumables, and the instrument into a single validated workflow. The laboratory inherits the manufacturer validation, which compresses implementation, and accountability is unambiguous when something fails. The price is reagent flexibility: you run what the platform vendor supplies, at prices the vendor sets. Open systems accept third-party reagents and offer real procurement leverage and menu breadth, but the laboratory carries verification responsibility for every assay-instrument combination it chooses to run. Between the two sits the increasingly common validated-open arrangement: an open chemistry qualified by the assay manufacturer on named instruments, with documented support. For shortlisting purposes the question is not which philosophy is superior but which verification obligations your quality system can actually absorb.
Build the compatibility matrix before the shortlist
The matrix is a one-page grid — candidate assays against installed and planned instruments — that scores each combination against the dimensions that decide whether it will run in routine service:
- Chemistry and amplification format supported by the instrument module set, including any pre-analytical extraction the assay assumes
- Fluorescence channels and filter sets, checked against every dye in the assay panel, including any internal control channel
- Consumable format compatibility: strips, plates, tubes, or cartridges, including thermal cycler block fit and seal compatibility
- Sample input format and volume requirements against your primary tubes and aliquoting workflow
- Software: result interpretation, export formats, and LIS middleware compatibility, including who maintains the assay definition files
- Regulatory status of the specific assay-instrument combination in your market, not of the assay alone
Score each cell as validated, compatible-with-verification, or incompatible, and require documentary evidence — a listing, a compatibility letter, or a verification protocol — for every "validated" claim. Suppliers answer questionnaires optimistically; the matrix forces the optimism into a checkable claim.
Assess lock-in and exit costs
Compatibility has a time dimension. A combination that is supported today may be withdrawn when a platform generation retires, so weigh the manufacturer’s stated commitments on reagent availability and on supporting the assay on future instrument generations. Where a single supplier would control both instrument and reagent supply after this purchase, model the pricing consequences explicitly — multi-year reagent supply agreements, price-escalation caps, and second-source options are standard mitigations. Finally, estimate the cost of exit: what re-validation on an alternative platform would require in labour and documentation, since that figure is the honest measure of how locked-in each option leaves you. A shortlist built from this matrix tends to be shorter, better priced, and far less eventful in year three.