# A guide to selecting high-performing antibodies for Alpha-1-antitrypsin (UniProt ID: P01009) for use in western blot, immunoprecipitation and flow cytometry

## TL;DR

This paper evaluates 18 antibodies for detecting Alpha-1-antitrypsin in various experiments to help researchers choose reliable ones.

## Contribution

The study provides a systematic validation of antibodies for A1AT using a standardized knockout cell line.

## Key findings

- Eighteen commercial antibodies were tested for western blot, immunoprecipitation, and flow cytometry.
- Results were validated using a SERPINA1 knockout and isogenic control in Hep G2 cells.
- The findings aim to improve antibody reproducibility and support reliable A1AT detection.

## Abstract

Alpha-1-antitrypsin (A1AT), encoded by the
SERPINA1 gene, is a circulating serine protease inhibitor that protects the lung from neutrophil elastase–mediated tissue damage. Mutations in
SERPINA1 cause alpha-1-antitrypsin deficiency, one of the most common hereditary causes of respiratory disease, leading to early-onset emphysema and chronic obstructive pulmonary disease, as well as hepatic complications. Given the clinical significance of A1AT and its widespread use as a biomarker, there is a critical need for high-quality antibodies to ensure reliable detection and mechanistic insights. Here we systematically characterised eighteen commercial antibodies for western blot, immunoprecipitation, and flow cytometry using a standardized knockout validation approach in human Hep G2 cells, comparing readouts in a
SERPINA1 knockout line with its isogenic parental control. This work is part of a broader collaborative initiative aimed at addressing antibody reproducibility by characterising commercial antibodies for human proteins and openly sharing the results with the community. While antibody use and protocols vary between laboratories, we encourage readers to use this report as a guide to select the most appropriate antibodies for their specific experimental needs.