Präanalytik

Präanalytik, the pre-analytical phase, is everything that happens to a sample before an analyser measures it. That includes whether the customer was fasting, which tube was used, how full the tube was, what temperature the sample was held at and how long it took to reach the laboratory.

Most avoidable error in blood testing belongs to this phase and not to the analysis, because an underfilled or haemolysed tube produces a number that looks ordinary while being wrong. Every collection method has its own pre-analytical rules, so a capillary kit posted from a customer's kitchen and a venous draw in a clinic are two different risk profiles.

A supplier who cannot describe these rules per marker is a supplier whose rejected samples become your refunds and your support tickets.

• Ask which tube type and filling volume each marker on your panel requires.
• Ask what the laboratory does with a sample received outside its stability window.
• Ask how the collection instructions reach your customer and in which languages.
• Ask what share of samples are rejected and for which stated reasons.

In this glossary, Probe explains the sample itself, Kapillarblut covers the collection method with the tightest handling rules, and Time-to-Result covers the clock that starts once the sample is collected.