Abstract
Bats are endowed with a remarkable capacity to withstand important pathogens through evolutionary adaptations in their immune systems. Antibodies are essential components of the adaptive immune response and serve as crucial biomarkers, indicating both present and past pathogen infections, as well as the overall physiological state of the organism. The main type of antibody found in the blood of mammals is IgG, produced as a result of specific T cell-dependent antibody responses. Currently, there is no simple technique for measuring absolute IgG concentration that can be applied to diverse species of bats. The present study proposes a methodology to quantify total IgG levels in bats. The approach is based on an immunosorbent assay and employs only protein G as a detecting reagent for IgG. As a proof of concept, we present a detailed procedure to quantify serum IgG in Egyptian fruit bats (Rousettus aegyptiacus). This method employs a standard curve generated by reconstituting previously IgG-depleted serum with defined concentrations of purified IgG. The estimated concentration of IgG was found to be relatively high (5–6 mg/ml), highlighting the role of specific antibody responses in the immune defence of bats. The method was also tested on two additional taxa, Myotis myotis (Vespertilionidae) and Miniopterus schreibersii (Miniopteridae), to assess its broader applicability. While the lack of protein G binding in M. schreibersii underscores a limitation of the assay, we propose an alternative strategy that extends its applicability in that case. This simple and effective technique offers a valuable tool for advancing our understanding of immune function in bats and potentially other wild mammals, contributing to broader efforts in wildlife immunology and disease ecology.
Acknowledgements
The experimental work was by INSERM. N.T. was re supported by fellowships from the French Institute Bulgaria (Institut français de Bulgarie). The zookeepers and veterinary staff of Copenhagen Zoo are thanked for their assistance in operations surrounding the restraint and anaesthesia of the captive bats. We are grateful to Angel Ivanov, Maxim Kolev and Stela-Teodora Trendafilova, who assisted in the collection of the blood samples in Bulgaria.
Funding
The fieldwork for this study was supported by the Bulgarian National Science Fund, project КП-06-Н51/9 “Caves as a reservoir for novel and reoccurring zoonoses — ecological monitoring and metagenomic analysis in real time.” NT and SD were supported by the Bulgarian National Science Fund (KP-06-Rila/2 from 08.12.2025). F.T. has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska- Curie grant agreement No 101034345. D.G.S. was funded by a Wellcome Trust Senior Research Fellowship (217221/Z/19/Z).
Author information
Authors and Affiliations
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing interests.
Additional information
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary Information
Below is the link to the electronic supplementary material.
Supplementary Material 1 (download PPTX )
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.
Reprints and permissions
About this article
Cite this article
Touzalin, F., Bertelsen, M.F., Tahas, S.A. et al. Quantification of absolute IgG concentration in bat sera.
Sci Rep (2026). https://doi.org/10.1038/s41598-026-68568-6
Received:
Accepted:
Published:
DOI: https://doi.org/10.1038/s41598-026-68568-6
Keywords
- Bats
- Antibodies
- IgG concentration
- ELISA
- Immune assays
Source: Ecology - nature.com
