7a. Molecular Diagnostics Teaching

Molecular Diagnostics is a brach of diagnostics based on the the detection and measurement of genetic material or proteins associated with a specific health condition/disease.

If you are interested in learning more about Molecular Diagnostics, you can browse below through several Molecular Diagnostics concepts brought to you by the OSU Medical Laboratory Science Senior class (2015). If you are interested in learning even more, check out the Molecular Diagnostics course (lecture listed as MEDLBS 5400), taught at OSU in Autumn.


Molecular Diagnostics Concepts Definitions brought to you by Ohio State University’s Medical Laboratory Science Class of 2015. Thank you all for a great job!

DNA, by Ashley Bryant

DNA (DeoxyRibonucleic Acid) is the blueprint of who we are. DNA houses the instructions that we as humans need in order to live, survive and reproduce. DNA is in every cell in the human body that has a nucleus. DNA is a very popular molecule that resembles a slinky or a twisted ladder commonly known as a double helix. This structure was discovered by Rosalind Franklin and also by Francis Crick, Maurice Wilkins and James Watson. DNA is tightly coiled into structures that look like butterflies called chromosomes. Humans have 23 pairs of chromosomes.

Mutations and genomic/DNA testing, by Ashley Bryant

Since we know that DNA is the blueprint for our lives we should also know that sometimes these complicated blueprints can contain mistakes. Genetic testing, a type of Molecular Diagnostics, can be done to reveal these mistakes and help doctors to diagnose diseases and identify genes that are damaged.

FISH (Fluoresce In Situ Hybridization), by Kristen Burgett

FISH is a procedure that allows individuals to locate the position of specific DNA sequences on chromosomes using a fluorescent probe. Researchers or Cytogeneticists use a colored marker, called a fluorescent probe, that identifies specific sequences on chromosome that cause certain diseases or abnormalities. For example, when individuals go fishing one must choose the right type of fishing pole and bait to catch certain types of fish. If the right bait is not used, fish will not bite and one will come out short-handed. The Fluoresce In Situ Hybridization method is like fishing, where you have to select the  fluorescent probe that “appeals to”/binds and therefore identifies the targeted area of interest. As my father would go fishing on Lake Erie to catch his perch or walleye, scientists go fishing to identify chromosomal abnormalities.

Next Generation Sequencing, by Ahlam Elhaouzi. 

Next generation sequencing (NGS) encompasses the novel technologies that allow to sequence the genetic material called DNA and RNA. If we consider DNA or RNA as words, we can say that sequencing is the spelling of these words and that disease/phenotypic appearance is the pronunciation of these words. NGS technologies are very helpful in finding any “misspelled words”, called gene mutations. Since gene mutations can cause disease, NGS help in the diagnosis of many clinical problems as well as the correct therapeutic decision making or preventing some diseases in a high risk person. Some common Next Generation sequencers are Roche454, Illumina/Solexa sequencing, Applied Biosystems SOLiDTM System, Helicos HeliscopeTM and Pacific Biosciences SMRT. Next Generation Sequencing includes four main steps: Library preparation, cluster generation, sequencing and data analysis.

Acute Lymphoblastic Leukemia (ALL), by Kyle Hiers

ALL stands for Acute lymphocytic Leukemia, or Acute Lymphoblastic Leukemia. It is a cancer that starts with the early version of lymphocytes. The cancer takes place in the bone marrow where the immature lymphocytes are found. The cancer is an acute cancer, which means it proceeds quickly and could be fatal within a few months if not treated. Also, the cancer can easily spread to other parts of the body including the central nervous system.

Trisomy, by Kyle Jablonski

Most humans have 46 chromosomes, composed of 23 pairs of chromosomes with one member of each pair being inherited from each parent. Trisomy is the addition of a chromosome to one of these chromosomal pairs, resulting in a 3 chromosome set with 47 chromosomes total. One of the most common and notable cases of trisomy is Trisomy 21, also known as Down’s Syndrome, in which a third copy of the 21st chromosome results in severe mental retardation and physical delays/abnormalities.

Philadelphia Chromosome, by Ayako McGregor

To understand the Philadelphia Chromosome, imagine there are two people. One is called chromosome 9, the other is called chromosome 22. Imagine that they swapped one of their arms. Now chromosome 22 with the new arm from chromosome 9 is called Philadelphia chromosome. In scientific terms: it is a specific karyotype defect in chromosome 22, where there is the translocation between chromosome 9 and 22 indicated as t(9:22)(q34:q11). “q” represents the long arm of the chromosome. In chromosome 9 region 3 band 4 is the break point and in chromosome 22 region 1 band 1 is the break point. The segment broken off from chromosome 9 is attached to chromosome 22 which makes the Ph chromosome.

Ploidy (Hypo/Hyper/Aneu/Di-ploid), by Morgan Reed

Normally each individual is considered diploid because we get a pair of chromosomes; One from our mother and one from our father. However, mutations occur where we do not have two chromosomes, but none, one, even three or more. Aneuploidy means having more or less than the expected number of chromosomes. In each person we expect 46 chromosomes and having aneuploidy could mean a gain or loss of chromosomes. Hyopdiploidy is a loss of a chromosome, such as in Turner’s syndrome, where hyperdiploidy is when we have an extra chromosome, such as in Down’s syndrome or Trisomy 21.

Kinome and Imatinib, by Tyler Sparrow

The kinome is the set of protein kinases in the genome that assist in catalyzing phosphorylation reactions of amino acids. These can be major targets in drug treatments that are used to control cell behavior and replication of cancer cells.

Imatinib is part of a class of medications called ‘kinase inhibitors’ that works by blocking the action of the abnormal protein, a kinase, that signals cancer cells to multiply. Successful treatment with this drug should help prevent the spread of the cancer cells.

Exome, by Rebekah Zets

When your genome (DNA) is transcribed into mRNA, some editing must be done to the pre-mRNA transcript before it can be considered mature RNA. This is done so that the information makes sense when it is translated into a protein. The editing is called splicing. During splicing, introns are removed so that all that remains are segments called exons.

For example:
1.) pre-mRNA transcript:
2.) Splicing takes place and unnecessary introns are removed:                    Iskjdfhiwuloveakjadhufiamolecularabjdbaidiagnosticsnbaiurh
3.) We are left with exons who are now ready to be translated:

Therefore, the portion of your genome that is formed by exons and named your exome!

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