title: Reliable detection of epigenetic histone marks and nuclear proteins in tissue cryosections.
abstract: Nuclear processes in real tissues often are significantly different from those in cultured cells. However, immunostaining on tissue sections needs long fixation which masks antigens and, respectively, antigen retrieval which restores antigen accessibility. These treatments affect the immunostaining results and complicate their interpretation. The problem is especially significant for nuclear antigens which often are very sensitive to both fixation and antigen retrieval. We targeted this problem by a study of several histone modifications and nuclear proteins in tissue sections of mouse retina which contains cells with both conventional and unique inverted nuclei. In the latter, the main chromatin classes form separate concentric shells which simplifies evaluation of the signal distribution. We show that as a rule, longer fixation demands longer antigen retrieval time. Nevertheless, antigens are remarkably diverse in this respect and need individual adjustment. We suggest a robust procedure for immunostaining on sections, that is, a method that allows controlling the differences in immunostaining caused by differences in fixation time and antigen retrieval duration, so that immunostaining protocol can be quickly optimized.
authors.affiliation: Department of Biology II, Biocenter Ludwig-Maximilians University Munich, Grosshadernerstrasse 2, 82152, Planegg-Martinsried, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Eberhart
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kimura
authors.forename: Heinrich
authors.initials: H
authors.lastname: Leonhardt
authors.forename: Boris
authors.initials: B
authors.lastname: Joffe
authors.forename: Irina
authors.initials: I
authors.lastname: Solovei
mesh_terms: D000818:Animals; D002467:Cell Nucleus; D016616:Cryoultramicrotomy / Q000379:methods; D044127:Epigenesis, Genetic; D006657:Histones / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D018613:Microscopy, Confocal; D009474:Neurons / Q000166:cytology; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D016612:Paraffin Embedding; D012160:Retina / Q000166:cytology; D013194:Staining and Labeling / Q000379:methods*; D016707:Tissue Fixation / Q000379:methods
chemical_list: D006657:Histones; D009687:Nuclear Proteins