Disrupting Endotoxin Masking in the Monocyte Activation Test
using PYROSPERSE® Dispersing Agent
What Makes This White Paper Essential
The Rabbit Pyrogen Test becomes non-compendial in Europe by January 2026
FDA initiatives continue to support the reduction of animal testing requirements
MAT is now the leading alternative — but only when masking is effectively addressed
As animal-based pyrogen tests are phased out, MAT is becoming the leading in-vitro standard. But endotoxin masking remains a major challenge that can lead to false negatives and compliance risks.
To address masking effects, dispersing agents have long been used in bacterial endotoxin testing (BET). One such additive —PYROSPERSE® Dispersing Agent, commercialized by Lonza — is widely adopted in BET workflows. However, its compatibility with PyroCell® — Lonza’s Monocyte Activation Test kit — had never been evaluated.
Could PYROSPERSE® Dispersing Agent enhance endotoxin detection in PyroCell® MAT?
Solvias set out to answer this question.
Because MAT is a cell-based assay, introducing any additive brings new uncertainties. It could stimulate immune cells, causing false-positive results, reduce cell viability, causing false-negative results, or simply have no effect in the assay. The results of the study challenge assumptions and demonstrate the feasibility of incorporating PYROSPERSE® Dispersing Agent into MAT workflows to improve endotoxin detection in challenging sample matrices, providing a strong basis for its broader application across diverse drug product types and formulation conditions.