Why DiaSorin’s LIAISON SARS-CoV-2 TrimericS IgG assay still matters in crowded COVID testing

Reviewed: ad hoc news Software & Services desk. Edited and checked on 2026-06-18, 21:33. Details in the imprint.

The LIAISON SARS-CoV-2 TrimericS IgG assay is one of those lab tools that looks almost boring from the outside, yet quietly shapes how doctors and public-health teams read the pandemic’s long echo in everyday blood samples.

What this assay actually measures

In simple terms, the LIAISON SARS-CoV-2 TrimericS IgG assay measures IgG antibodies directed against the full trimeric spike protein of SARS-CoV-2, not just a single fragment of it. This broader target design aims to mirror how the virus presents itself on the surface of infected cells.

Instead of delivering a binary positive-or-negative result, the test provides a quantitative value in BAU/ml aligned with the WHO international standard. That number lets labs follow how antibody levels rise after vaccination, flatten out, or drop months later.

How it fits into DiaSorin’s LIAISON ecosystem

The assay runs on DiaSorin’s fully automated LIAISON and LIAISON XL analyzers, slotting into existing instrument menus without new hardware. For a lab technician, it means loading specific reagent cartridges and letting the instrument handle the chemiluminescent immunoassay steps.

DiaSorin describes the test as calibrated against the WHO standard and traceable to Binding Antibody Units, which eases comparison between different labs and studies. That is a subtle but important detail when clinicians want to compare their local data with international research.

Use cases from booster shots to epidemiology

Hospitals and vaccination centers use the TrimericS IgG assay to monitor immune response after infection or vaccination, especially in risk groups with compromised immune systems. Instead of guessing, they can see whether antibody levels reach defined thresholds after a booster.

Public-health teams and researchers also rely on quantitative assays like this for seroprevalence studies, mapping how many people in a region, or in a specific patient cohort, show measurable antibodies over time. That helps refine booster strategies and communication.

Strengths and practical limitations

One clear strength is the assay’s focus on the full trimeric spike, which can capture antibodies against multiple epitopes and potentially maintain performance when variants alter single regions. The quantitative WHO-aligned readout is another practical plus.

Yet the test has limits that DiaSorin itself stresses: a high antibody value does not guarantee protection, and the assay does not diagnose acute infection or replace PCR or antigen tests. It is a tool for immune monitoring, not for deciding whether someone is currently contagious.

Where labs can get it and under what conditions

The LIAISON SARS-CoV-2 TrimericS IgG assay is offered to clinical laboratories and hospitals that operate LIAISON platforms, primarily under CE-IVD marking and, where applicable, under local regulatory authorizations. It is not a direct-to-consumer test.

DiaSorin highlights stability and standardized handling on its automated platforms, which matters for high-throughput environments processing hundreds of samples per shift. Stock management revolves around reagent kits, quality controls, and calibrators that plug into existing workflows.

Company context and the stock angle

The TrimericS IgG assay is one element in DiaSorin’s broader immunodiagnostics and molecular portfolio, which spans infectious diseases, endocrinology, and oncology. It helped the group capture pandemic-related demand while building a menu that remains relevant beyond acute COVID waves.

Shares of DiaSorin S.p.A. (IT0003497168) trade on Borsa Italiana’s Euronext Milan, giving investors exposure to the company’s LIAISON-based diagnostic strategy.

This article was AI-assisted and editorially reviewed. Product information without guarantee; prices and availability may change at short notice. No investment advice, no buy or sell recommendation. Stock-market transactions involve risks up to total loss.