TY - JOUR
T1 - Effects of formalin fixation, paraffin embedding, and time of storage on DNA preservation in brain tissue
T2 - A brainnet Europe study
AU - Ferrer, Isidre
AU - Armstrong, Judith
AU - Capellari, Sabina
AU - Parchi, Piero
AU - Arzberger, Thomas
AU - Bell, Jeanne
AU - Budka, Herbert
AU - Ströbel, Thomas
AU - Giaccone, Giorgio
AU - Rossi, Giacomina
AU - Bogdanovic, Nenad
AU - Fakai, Peter
AU - Schmitt, Andrea
AU - Riederers, Peter
AU - Al-Sarraj, Safa
AU - Ravid, Rivka
AU - Kretzschmar, Hans
PY - 2007/7
Y1 - 2007/7
N2 - There is a large amount of tissue stored in brain collections and brain banks, but little is known about whether formalin-fixed tissues and paraffin blocks stored for years in brain banks are suitable for the retrospective genetic studies. The study was carried out in order to: (i) compare DNA preservation in frozen, formalin-fixed and paraffin-embedded tissues stored for different periods; (ii) study point mutations and triplet expansions in frozen, formalin-fixed and paraffin-embedded material stored for variable periods, and using different fixative solutions; (iii) compare different methods to optimize DNA extraction and DNA amplification from suboptimally preserved brain tissue. DNA preservation is suitable for genetic studies in samples stored at -80°C for several years. Formalin-fixed, paraffin-embedded tissue was inferior to frozen tissue, but did yield adequate results in many cases depending on the type of fixative solution and time of fixation before embedding. Prolonged fixation in formalin rarely yielded useful DNA. Similar results were obtained in samples from prion diseases. The best results were obtained by using the Qiagen kits (QIAmp DNA Micro) in frozen material, paraffin blocks and formalin-fixed tissue. Genomiphi™ and TaKaRa Ex Taq™ methods were also assayed in paraffin blocks and in formalin-fixed samples with limited success.
AB - There is a large amount of tissue stored in brain collections and brain banks, but little is known about whether formalin-fixed tissues and paraffin blocks stored for years in brain banks are suitable for the retrospective genetic studies. The study was carried out in order to: (i) compare DNA preservation in frozen, formalin-fixed and paraffin-embedded tissues stored for different periods; (ii) study point mutations and triplet expansions in frozen, formalin-fixed and paraffin-embedded material stored for variable periods, and using different fixative solutions; (iii) compare different methods to optimize DNA extraction and DNA amplification from suboptimally preserved brain tissue. DNA preservation is suitable for genetic studies in samples stored at -80°C for several years. Formalin-fixed, paraffin-embedded tissue was inferior to frozen tissue, but did yield adequate results in many cases depending on the type of fixative solution and time of fixation before embedding. Prolonged fixation in formalin rarely yielded useful DNA. Similar results were obtained in samples from prion diseases. The best results were obtained by using the Qiagen kits (QIAmp DNA Micro) in frozen material, paraffin blocks and formalin-fixed tissue. Genomiphi™ and TaKaRa Ex Taq™ methods were also assayed in paraffin blocks and in formalin-fixed samples with limited success.
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U2 - 10.1111/j.1750-3639.2007.00073.x
DO - 10.1111/j.1750-3639.2007.00073.x
M3 - Article
C2 - 17465988
AN - SCOPUS:34347249613
VL - 17
SP - 297
EP - 303
JO - Brain Pathology
JF - Brain Pathology
SN - 1015-6305
IS - 3
ER -