title: The effects of frozen tissue storage conditions on the integrity of RNA and protein.
abstract: Unfixed tissue specimens most frequently are stored for long term research uses at either -80° C or in vapor phase liquid nitrogen (VPLN). There is little information concerning the effects such long term storage on tissue RNA or protein available for extraction. Aliquots of 49 specimens were stored for 5-12 years at -80° C or in VPLN. Twelve additional paired specimens were stored for 1 year under identical conditions. RNA was isolated from all tissues and assessed for RNA yield, total RNA integrity and mRNA integrity. Protein stability was analyzed by surface-enhanced or matrix-assisted laser desorption ionization time of flight mass spectrometry (SELDI-TOF-MS, MALDI-TOF-MS) and nano-liquid chromatography electrospray ionization tandem mass spectrometry (nLC-ESI-MS/MS). RNA yield and total RNA integrity showed significantly better results for -80° C storage compared to VPLN storage; the transcripts that were preferentially degraded during VPLN storage were these involved in antigen presentation and processing. No consistent differences were found in the SELDI-TOF-MS, MALDI-TOF-MS or nLC-ESI-MS/MS analyses of specimens stored for more than 8 years at -80° C compared to those stored in VPLN. Long term storage of human research tissues at -80° C provides at least the same quality of RNA and protein as storage in VPLN.
authors.affiliation: Functional Genomics Core, Institute for Research in Biomedicine , Barcelona , Spain.
authors.forename: H
authors.initials: H
authors.lastname: Auer
authors.forename: J A
authors.initials: JA
authors.lastname: Mobley
authors.forename: L W
authors.initials: LW
authors.lastname: Ayers
authors.forename: J
authors.initials: J
authors.lastname: Bowen
authors.forename: R F
authors.initials: RF
authors.lastname: Chuaqui
authors.forename: L A
authors.initials: LA
authors.lastname: Johnson
authors.forename: V A
authors.initials: VA
authors.lastname: Livolsi
authors.forename: I A
authors.initials: IA
authors.lastname: Lubensky
authors.forename: D
authors.initials: D
authors.lastname: McGarvey
authors.forename: L C
authors.initials: LC
authors.lastname: Monovich
authors.forename: C A
authors.initials: CA
authors.lastname: Moskaluk
authors.forename: C A
authors.initials: CA
authors.lastname: Rumpel
authors.forename: K C
authors.initials: KC
authors.lastname: Sexton
authors.forename: M K
authors.initials: MK
authors.lastname: Washington
authors.forename: K R
authors.initials: KR
authors.lastname: Wiles
authors.forename: W E
authors.initials: WE
authors.lastname: Grizzle
authors.forename: N C
authors.initials: NC
authors.lastname: Ramirez
mesh_terms: D003080:Cold Temperature; D005615:Freezing; D020869:Gene Expression Profiling; D006801:Humans; D046228:Microarray Analysis; D009369:Neoplasms / Q000473:pathology; D011506:Proteins / Q000737:chemistry*; D040901:Proteomics / Q000379:methods; D012313:RNA / Q000737:chemistry*; D012333:RNA, Messenger / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014021:Tissue Preservation / Q000379:methods*
chemical_list: D011506:Proteins; D012333:RNA, Messenger; D012313:RNA
keywords: RNA; assays; human tissues; proteomics; storage; temperatures