# Toward Comprehensive In Vitro Evaluation of Serum Albumin Binding of Per- and Polyfluoroalkyl Substances

## TL;DR

This paper reviews methods for measuring how per- and polyfluoroalkyl substances bind to serum albumin, a key protein in blood, and highlights a promising technique for accurate and rapid assessment.

## Contribution

The paper introduces differential scanning fluorimetry as a reliable and sensitive method for evaluating serum albumin–PFAS binding.

## Key findings

- Existing methods for measuring PFAS binding affinities produce inconsistent results due to varying experimental conditions.
- Differential scanning fluorimetry offers a rapid and reproducible approach for in vitro assessment of protein–PFAS interactions.
- Serum albumin is a critical target for PFAS due to its role in transport and toxicokinetics.

## Abstract

Per- and polyfluoroalkyl substances (PFAS) constitute a large and chemically diverse class of synthetic compounds characterized by one or more fully fluorinated methyl or methylene groups. Many PFAS are toxic, environmentally persistent, bioaccumulative, and highly mobile, resulting in widespread contamination and biological exposure. Across taxa PFAS exhibit affinity for proteins and preferentially accumulates in protein-rich, highly perfused tissues. Protein binding critically influences PFAS distribution, bioaccumulation, toxicity, and elimination. A variety of different approaches for determining bind affinity have existed for decades; however, depending on experimental conditions, calculated affinities can vary over multiple orders of magnitude which limits comparison of protein–PFAS binding affinities across studies and across PFAS chemical space. Addressing this limitation requires robust and standardized experimental platforms capable of rapidly generating quantitative binding data. Among the most important targets is serum albumin—the principal transport protein in vertebrate blood—which plays a central role in governing PFAS toxicokinetics. This review summarizes current methodologies for measuring protein–PFAS binding affinities, evaluates the strengths and limitations of each approach, synthesizes the existing literature on serum albumin–PFAS interactions, and highlights differential scanning fluorimetry as a rapid, reproducible, and sensitive technique for in vitro assessment of relative protein–PFAS binding.