Protein Detection Using the Multiplexed Proximity Extension Assay (PEA) from Plasma and Vaginal Fluid Applied to the Indicating FTA Elute Micro Card™

Malin Berggrund; Daniel Ekman; Inger Gustavsson; Karin Sundfeldt; Matts Olovsson; Stefan Enroth; Ulf Gyllensten

doi:10.33393/jcb.2016.2077

Authors

Malin Berggrund Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Biomedical Center, Uppsala University, Uppsala, Sweden
Daniel Ekman Olink Bioscience AB, Dag Hammarskjölds väg, Uppsala, Sweden
Inger Gustavsson Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Biomedical Center, Uppsala University, Uppsala, Sweden
Karin Sundfeldt Department of Obstetrics and Gynecology, Institute for Clinical Sciences, Sahlgrenska Cancer Center, Gothenburg University, Gothenburg, Sweden
Matts Olovsson Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden
Stefan Enroth Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Biomedical Center, Uppsala University, Uppsala, Sweden
Ulf Gyllensten Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Biomedical Center, Uppsala University, Uppsala, Sweden

DOI:

https://doi.org/10.33393/jcb.2016.2077

Keywords:

FTA Elute Card, Vaginal Fluid, Plasma, Proximity Extension Assay

Abstract

The indicating FTA elute micro card™ has been developed to collect and stabilize the nucleic acid in biological samples and is widely used in human and veterinary medicine and other disciplines. This card is not recommended for protein analyses, since surface treatment may denature proteins. We studied the ability to analyse proteins in human plasma and vaginal fluid as applied to the indicating FTA elute micro card™ using the sensitive proximity extension assay (PEA). Among 92 proteins in the Proseek Multiplex Oncology Iv2 panel, 87 were above the limit of detection (LOD) in liquid plasma and 56 among 92 above LOD in plasma applied to FTA cards. Washing and protein elution protocols were compared to identify an optimal method. Liquid-based cytology samples showed a lower number of proteins above LOD than FTA cards with vaginal fluid samples applied. Our results demonstrate that samples applied to the indicating FTA elute micro card™ are amendable to protein analyses, given that a sensitive protein detection assay is used. The results imply that biological samples applied to FTA cards can be used for DNA, RNA and protein detection.