Molecular Pathology
Written By: Misha Patel
Molecular pathology is an emerging field of medicine which studies organs, tissues, or body fluids in order to diagnose certain diseases. This field involves the application of techniques through biochemistry, cell biology, molecular biology, proteomics, and genetics. Molecular pathology relies on the usage of labeled antibodies and slide or fluid-based nucleic acids.
Cancer and other infectious diseases are commonly diagnosed with molecular pathology. Some of the complex techniques that are used for diagnoses are multiplex PCR, in situ hybridization, and DNA sequencing. After diagnosis, molecular testing can help provide appropriate therapies by pinpointing therapeutic targets in new drugs.
Another method of molecular pathology includes in situ hybridization. This process establishes a noncovalent sequence-specific interaction between DNA in a piece of tissue and a complementary DNA strand. This is called slide-based ISH and is another tool commonly used instead of histopathology.
The most familiar diagnostic technique is Polymerase Chain Reaction, also known as ] PCR. This includes a genetic rearrangement, which is great for distinguishing tests. A PCR cycle involves 3 obligatory steps; denaturing, annealing, and polymerization. In the first step of denaturation, the helix of the DNA unwinds. In annealing, oligonucleotides primers bind to complementary bases on the two DNA strands. Lastly, during polymerization, the polymerase adds the nucleotides to the template strand, finalizing with two strands of DNA. When completing this process, there will be thousands of DNA strands. PCR can amplify RNA and be used to detect HIV and Hepatitis C.
The last molecular diagnostic technique is spectral karyotype imaging. This method is based on the use of 23 sets of chromosome-specific “painting” probes. The probes are traced with three different fluorescent dyes. A device called the interferometer assigns a visual color to the chromosomes. Then, a cell karyotype is designated to the chromosome pairs and a pathologist identifies any numerical chromosomal abnormalities.
In conclusion, molecular pathology is a relatively new field that can be used to diagnose diseases in a different and modern way. The three methods stated above are being used to cure a variety of different diseases such as cancer and HIV. These molecular techniques also help provide better treatment options to patients as well.
Sources
Netto, George J et al. “Diagnostic molecular pathology: current techniques and clinical applications, part I.” Proceedings (Baylor University. Medical Center) vol. 16,4 (2003): 379–83. doi:10.1080/08998280.2003.11927931
Warshawsky, Ilka. “Molecular Pathology.” Molecular Pathology — an Overview | ScienceDirect Topics, 2010, www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/molecular-pathology
