R-Universal Buffer for Antigen Retrieval in Tissue Arrays

Aptum’s R-Universal buffer provides uniform and effective antigen retrieval across diverse tissue types. It is widely used in processing tissue microarrays for immunohistochemistry, proteomics, and histological studies, particularly in cancer research, neurology, and developmental biology. Common downstream applications include staining for phosphorylated proteins, cell differentiation markers, and oncogenic signaling molecules.

An important application of the R-Universal buffer is in the preparation of tissue arrays. Research laboratories analyzing tissues from transgenic animals, experimental models, or collections of human samples greatly benefit from using tissue arrays, as they enable the simultaneous processing and immunostaining of a large number of samples in a single experiment. To support this work, we offer a highly regarded Manual Tissue Arrayer, widely accepted by the research community.

Tissue arrays are typically composed of carefully selected specific areas of tissue, often including unique and irreplaceable samples. Therefore, a standardized and reliable antigen retrieval method is essential to preserve sample integrity and ensure high-quality immunostaining results.

We recommend using our 2100 Retriever, which has become a gold standard for antigen retrieval. We also provide specialized tissue slides designed to covalently bind tissue sections, keeping them firmly attached and well-preserved during processing. Equally critical is the choice of retrieval buffer: R-Universal is a neutral pH buffer that effectively reduces chemical cross-linking caused by fixatives, removes excess fixative, eliminates metal ion deposits resulting from formalin fixation, and — when used in combination with the 2100 Retriever — helps proteins regain their native configuration (see also).

Here we show semi-quantitative staining of tissue arrays after epitope recovery with R-Universal. From: Aakula, A. et al (2023). PP2A methylesterase PME-1 suppresses anoikis and is associated with therapy relapse of PTEN-deficient prostate cancers. Molecular Oncology 17, 1007–1023. https://doi.org/10.1002/1878-0261.13353

To illustrate the effectiveness of R-Universal, below is a list of published studies where it has been successfully used for antigen retrieval in tissue arrays.

Luijerink, L., & Waters, K.A. (2021).Immunostaining for NeuN does not show all mature and healthy neurons in the human and pig brain: focus on the hippocampus.→ Treatment of brain tissue microarrays with R-Universal buffer for NeuN staining.Read here

Rupp, C. et al. (2019).PP2A inhibitor PME-1 suppresses anoikis, and is associated with therapy relapse of PTEN-deficient prostate cancers.→ Prostate cancer tissue arrays processed with R-Universal buffer before antibody staining.PDF Link

Demuth, T., et al. (2008).Glioma cells on the run–the migratory transcriptome of 10 human glioma cell lines.→ Application of R-Universal buffer on glioma tissue microarrays for invasion analysis.PDF Full Text

Peng, Y., & Deutscher, S.L. (2017).Targeting aggressive prostate cancer-associated CD44v6 using phage display selected peptides.→ Human prostate cancer TMAs treated with R-Universal buffer for imaging analysis.Full Text

Xu, Y., et al. (2024).Reconstitution of human PDAC using primary cells reveals oncogenic transcriptomic features at tumor onset.→ Human pancreatic ductal adenocarcinoma tissue arrays treated with R-Universal buffer for IHC.PDF Download

He, X., et al. (2004).Investigation of the thermal and tissue injury behavior in microwave thermal therapy using a porcine kidney model.→ Antigen retrieval in tissue blocks and arrays was facilitated with R-Universal buffer.View Article

Isomursu, A., et al. (2023).PP2A methylesterase PME-1 suppresses anoikis and is associated with therapy relapse of PTEN-deficient prostate cancers.→ PCa tissue microarrays underwent R-Universal buffer treatment before staining.PDF Access

Murphy, D., et al. (2010).Constitutively overexpressed 21 kDa protein in Hodgkin lymphoma and aggressive non-Hodgkin lymphomas identified as cytochrome B5b (CYB5B).→ TMAs processed using R-Universal buffer prior to proteomic analysis.Read Study

Prater, A.R., et al. (2017).Targeting aggressive prostate cancer-associated CD44v6 using phage display selected peptides.→ Extensive R-Universal buffer use for TMA-based cancer biomarker analysis.Direct PDF