DNA extraction and analysis of amelogenin in samples fixed in formalin, embeded in paraffin and stored for 1 and 5 years in the Patology Department at UNIFESP

• Grant number: 08/11233-8
• Support Opportunities: Regular Research Grants
• Start date: April 01, 2009
• End date: March 31, 2011
• Field of knowledge: Health Sciences - Medicine - Pathological Anatomy and Clinical Pathology
• Principal Investigator: Edna Sadayo Miazato Iwamura
• Grantee: Edna Sadayo Miazato Iwamura
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

The biological research has progressed in recent decades with the development of molecular biology and genetics. Among these developments there is the polimerase chain reaction (PCR), which allows the amplification of small samples of DNA, enough to allow human identification. For this technique is possible to analyze and to identify the DNA obtained from hair bulbs, bones, saliva, blood, stains of sperm, histologic stained slides, among others. New approaches have emerged with the advent of this technique, as the retrospective analysis of tissues included in paraffin blocks for investigation of hereditary diseases, detection of infectious agents and genetic disorders. The ability to study DNA extracted from archival of formalin fixed tissue included in paraffin (FFTIP) enables valuable retrospective investigations. However, according to some authors is difficult to obtain genomic DNA of good quality, since the process of fixation often results in fragmentation of DNA. During formalin fixation, cross-links of protein-protein and protein-DNA interactions that are formed. In addition, the formaldehyde in the tissue gradually changes into formic acid, hydrolyzing the DNA. High quality of DNA for amplification is a limiting factor in such samples. The fixative used, the time of fixation, inclusion and storage conditions can contribute to the degradation of DNA. In order to evaluate the quality of DNA from fixed tissue embedded in paraffin, three methods of extraction will be tested and the amelogenin gene will be analyzed. Samples of normal liver, spleen and brain collected during the autopsy procedures, as well as liver spleen and brain samples obtained from different periods of storage (filed by 1 and 5 years) from the archives of the Department of Pathology, Federal University of São Paulo will be used. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

IWAMURA, EDNA S. MIAZATO; SOARES-VIEIRA, JOSE ARNALDO; SILVA, MARCELO SOUZA; FUNABASHI, KARINA S.; GODOY, CARLA D.; ROMERO MUNOZ, DANIEL. Analysis of DNA profiles extracted from degraded samples from archival of formalin fixed tissue included in paraffin (FFTIP) and hairs. FORENSIC SCIENCE INTERNATIONAL GENETICS SUPPLEMENT SERIES, v. 2, n. 1, p. 2-pg., 2009-12-01. (08/11233-8)

FUNABASHI, KARINA SILVA; BARCELOS, DENISE; VISONA, IRIA; SILVA, MARCELO SOUZA E; SOUSA, MARIA LUIZA ALMEIDA PRADO OLIVEIRA E; DE FRANCO, MARCELLO FABIANO; MIAZATO IWAMURA, EDNA SADAYO. DNA extraction and molecular analysis of non-tumoral liver, spleen, and brain from autopsy samples: The effect of formalin fixation and paraffin embedding. PATHOLOGY RESEARCH AND PRACTICE, v. 208, n. 10, p. 584-591, 2012. (08/11233-8)