The current and future applications of in situ hybridization technologies in anatomical pathology

Introduction: In situ hybridization (ISH) plays an important role in the field of molecular diagnostics, especially in an anatomical pathology laboratory. ISH is a technique that can detect the targeted DNA or RNA sequences in tissue sections from frozen or fixed materials with labeled DNA or RNA probes. Radioactive and non-radioactive probes are the two major probes that can be used to label the targeted nucleic acids. Areas covered: Two decades after the Human Genome Project, ISH has not only simply been applied to identify the chromosomal location of a human gene but has also been extensively applied to gene expressions studies and utilized for clinical diagnosis, especially for the determination of biomarkers for breast and ovarian cancers–human epidermal growth factor receptor 2. Duchenne muscular dystrophy, Cri-du-chat syndrome, Angelman syndrome, PraderWilli syndrome, cystic fibrosis, and trisomy are diseases that can also be detected by ISH. In this review, the basic principles, historical development, advantages and disadvantages, enhancement in reporting molecules and probes, advancement in detection methods, in situ PCR, clinical applications and novel applications of ISH will be discussed. Expert opinion: With the advancement in ISH technologies and appropriate training, diagnosis can be improved in Anatomical Pathology.