Immunodetection of Human LINE-1 Expression in Cultured Cells and Human Tissues

Methods Mol Biol. 2016;1400:261-80. doi: 10.1007/978-1-4939-3372-3_17.


Long interspersed element-1 (LINE-1) is the only active protein-coding retrotransposon in humans. It is not expressed in somatic tissue but is aberrantly expressed in a wide variety of human cancers. ORF1p protein is the most robust indicator of LINE-1 expression; the protein accumulates in large quantities in cellular cytoplasm. Recently, monoclonal antibodies have allowed more complete characterizations of ORF1p expression and indicated potential for developing ORF1p as a clinical biomarker. Here, we describe a mouse monoclonal antibody specific for human LINE-1 ORF1p and its application in immunofluorescence and immunohistochemistry of both cells and human tissues. We also describe detection of tagged LINE-1 ORF2p via immunofluorescence. These general methods may be readily adapted to use with many other proteins and antibodies.

Keywords: Biomarker; Immunofluorescence; Immunohistochemistry; LINE-1 ORF1p; Tissue microarray; Tumor marker; p40.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers
  • Cell Line
  • Fluorescent Antibody Technique*
  • Gene Expression*
  • Humans
  • Immunohistochemistry* / methods
  • Long Interspersed Nucleotide Elements*
  • Open Reading Frames*
  • Tissue Array Analysis* / methods


  • Biomarkers