How to choose a laboratory analyser: throughput, reagents, cost per test

In a laboratory, the price of the analyser is almost never the real subject. The subject is the cost per test over five years — reagents, calibrators, controls, consumables and servicing included. An analyser given away with expensive reagents is the most costly deal on the market.

1. Calculate your real volume, by parameter

Take twelve months of activity and count tests by family: biochemistry, haematology, immunoassay, haemostasis, microbiology, blood gases. Then identify your hourly peak, not your daily average. A laboratory receiving 70% of its samples between 7am and 10am must be sized for that window.

2. Quoted throughput is not real throughput

Manufacturers publish a theoretical maximum, often measured on a single simple parameter. Ask for the throughput on your request profile, including:

• calibration and quality control time at start-up;
• handling of urgent samples interrupting a run;
• automatic repeats when a result falls outside range.

The gap between quoted and usable throughput commonly reaches 30 to 40%.

3. Open or closed system: the question that decides the budget

• A closed system accepts only the manufacturer's reagents. You buy peace of mind and traceability, and you lose all negotiating leverage for ten years.
• An open system accepts third-party reagents. It lets you put suppliers in competition, at the cost of in-house validation work your laboratory must be able to carry.

Neither option is better in itself. But the choice must be deliberate, and costed before signature.

4. Cost per test: the only honest comparison

Ask every supplier to cost the following for your annual volume:

• reagent price per test, accounting for the dead volume of each cartridge;
• the cost of calibrators and controls, and their mandated frequency;
• on-board reagent stability — a reagent expiring in 7 days generates considerable waste on low volumes;
• consumables: cuvettes, tips, wash solutions, filters;
• the annual service contract, and what it excludes.

Reduce it all to a cost per test, then multiply by five years. The ranking of offers often reverses completely at this stage.

5. Connection to the information system

An unconnected analyser forces double data entry, and double entry produces wrong results. Check the interface to your LIS: supported protocol, bidirectional communication (does the analyser receive the worklist?), primary barcode reading, and above all who pays for the interface and who maintains it. It is a quotation line that is regularly forgotten.

6. Environment and continuity

Analysers are sensitive to their environment. Confirm the permissible temperature and humidity range, water requirements and water quality, liquid waste disposal, and tolerance to voltage variation. In many settings a correctly sized UPS is not optional: a power cut mid-run can lose the whole run and the reagents committed to it.

Your checklist

• Annual volume per parameter and hourly peak documented?
• Throughput verified against my request profile?
• Open or closed system — and the five-year consequence costed?
• Full cost per test, dead volume included?
• On-board stability compatible with my volume?
• Bidirectional LIS interface, included in the quotation?
• Response time and local parts stock?

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