Page 251 - Textbook of Pathology, 6th Edition

iii) Molecular diagnostic techniques. The group of mole- Study of oncogenic viruses at molecular level. 235
cular biologic methods in the tumour diagnostic laboratory Besides the application of these molecular techniques for
are a variety of DNA/RNA-based molecular techniques in diagnosis of tumour, many of he newer molecular techniques
which the DNA/RNA are extracted (compared from in situ are being applied for predicting prognosis, biologic
above) from the cell and then analysed. These techniques behaviour of tumour, detection of minimal residual disease
are highly sensitive, specific and rapid and have and for hereditary predisposition of other family members
revolutionised diagnostic pathology in neoplastic as well as to develop a particular cancer. CHAPTER 8
non-neoplastic conditions (e.g. in infectious and inherited iv) DNA microarray analysis of tumours. Currently, it is
disorders, and in identity diagnosis). Molecular diagnostic possible to perform molecular profiling of a tumour by use
techniques include: DNA analysis by Southern blot, RNA of gene chip technology which allows measurement of levels
analysis by northern blot, and polymerase chain reaction of expression of several thousand genes (up-regulation or
(PCR). The following techniques of molecular methods in down-regulation) simultaneously. Fluorescent labels are
tumour diagnosis have applications in haematologic as well used to code the cDNA synthesised by trigger from mRNA.
as non-haematologic malignancies: The conventional DNA probes are substituted by silicon chip Neoplasia
Analysis of molecular cytogenetic abnormalities which contains the entire range of genes and high resolution
Mutational analysis scanners are used for the measurement.
Antigen receptor gene rearrangement
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