Genomics Glossary for RNA Sequencing

complementary strands (of DNA)

two single opposing stands of DNA that bind as a result of base pairing throughout their full length


an organized collection of information that can be accessed, managed, and updated

deoxyribonucleic acid (DNA)

the molecule that encodes the information for all the characteristics or traits about an organism

DNA Sequencing

“Reading” the DNA molecule to determine the sequence of the letters

flow cell

a special glass plate that is a little larger than a microscope slide, which is used to attach DNA or cDNA (made from RNA) samples to sequence them in next-generation sequencing machines


a unit of DNA that controls specific traits

gene expression

the process by which instructions in our DNA are converted into functional products, such as proteins (read more about the basics of gene expression)

gene quantification

counting the number of reads we have assigned to each gene


all the DNA in an organism


the study of a large number of genes and their interactions and/or of entire genomes (all of the DNA in an organism) to learn what kind of information is coded in these DNA sequences and how the DNA instructions are carried out


the pieces of RNA that are removed from final messenger RNAs (these segments are not used to code for proteins)


A type of white blood cell in the immune system. Macrophages are responsible for "eating" and digesting cancer cells, microbes, and foreign materials.


alterations in the DNA


a cell that carries messages between the brain and other parts of the body. It is also called a "nerve cell" and is the basic unit of the nervous system.


the basic structural units of nucleic acids such as DNA and RNA. They are made up of a nucleoside coupled to a phosphate group

polymerase chain reaction (PCR)

A laboratory method using DNA polymerase [also in glossary] to make copies of DNA molecules.


short nucleotide sequences that serve as a starting point for DNA synthesis. They are required for DNA replication because DNA polymerase can only add nucleotides to an existing DNA strand.


large complex molecules that perform many critical roles for an organism to function

reverse transcriptase

An enzyme that makes a cDNA copy of an RNA molecule. This enzyme was originally discovered in viruses.

ribonucleic acid (RNA)

a nucleic acid molecule that is implicated in various biological roles, including coding, decoding, regulation, and expression of genes.

RNA sequencing (RNA-seq)

a technique that reveals the presence and quantity of RNA in a biological sample at a given moment in time.

RNA splicing

The process of editing messenger RNA during transcription through removal of introns. Exons are joined together through a process called ligation.


The process of determining the order of nucleotides that makes up DNA or RNA

sequencing adapters

Short pieces of DNA that attach a sequencing molecule to a sequencing flow cell via complementery base-pairing. These are required for a sequencing machine to recognize and read a molecule of DNA or cDNA.

sequencing reads

a list of short nucleotide sequences (100-200 letters, or base pairs (bp)


a sequence of one or more letters


the process in which information in a strand of DNA is decoded into a messenger RNA molecule