title: Housekeeping genes; expression levels may change with density of cultured cells.
abstract: Western blotting is a powerful technique to characterize a multitude of cellular proteins. As an internal control, the blots are commonly probed for "housekeeping" gene products. In this communication, we show that cell confluence significantly affects the levels of two such widely used proteins, alpha-tubulin and Glyceraldehyde-3-Phosphate Dehydrogenase. On the other hand the levels of heat-shock protein-90 and beta-actin remained unchanged at a wide range of cell densities, making these proteins into more reliable loading controls.
authors.affiliation: Department of Microbiology and Immunology, Queen's University, Kingston, Ontario, Canada K7L 3N6.
authors.forename: Samantha
authors.initials: S
authors.lastname: Greer
authors.forename: Rice
authors.initials: R
authors.lastname: Honeywell
authors.forename: Mulu
authors.initials: M
authors.lastname: Geletu
authors.forename: Rozanne
authors.initials: R
authors.lastname: Arulanandam
authors.forename: Leda
authors.initials: L
authors.lastname: Raptis
mesh_terms: D000199:Actins / Q000096:biosynthesis*; D000818:Animals; D015153:Blotting, Western / Q000379:methods; D002452:Cell Count; D005786:Gene Expression Regulation; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000096:biosynthesis*; D018841:HSP90 Heat-Shock Proteins / Q000096:biosynthesis*; D051379:Mice; D041681:NIH 3T3 Cells; D014404:Tubulin / Q000096:biosynthesis*
chemical_list: D000199:Actins; D018841:HSP90 Heat-Shock Proteins; D014404:Tubulin; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases