Biotechnology Terms Starting With R
Biotechnology Glossary: R
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Recombinant DNA
/ reh-KOM-bih-nunt dee-en-ay / · Latin recombinare, to combine again; Deoxyribonucleic Acid
Recombinant DNA is a laboratory-made DNA molecule constructed by joining DNA sequences from two or more different sources using restriction enzymes and DNA ligase.
The technology, pioneered by Herbert Boyer and Stanley Cohen in 1973, enabled genes from any organism to be inserted into bacterial plasmids for amplification and expression. Recombinant DNA formed the technical foundation of the modern biotechnology industry, enabling production of human proteins in microbial hosts, development of transgenic organisms, and molecular medicine. Safety concerns about recombinant DNA led to the historic 1975 Asilomar Conference, where scientists voluntarily established guidelines before regulatory frameworks existed.
Recombinant DNA joins DNA sequences that were not originally together. The method made it possible to produce many proteins in laboratory organisms.
How To Become An Internal Medicine Specialist? →Recombinant DNA must always mix DNA from different species. It can also combine DNA pieces from the same species in a new arrangement.
A plasmid carrying the human insulin coding sequence is recombinant DNA. Bacteria with that plasmid can produce insulin protein.
Recombinant Protein
/ ree-KOM-buh-nunt PROH-teen / · Latin re- (again) + combinare (to join together) + Greek proteios (primary)
A recombinant protein is a protein encoded by recombinant DNA. Scientists splice its gene into a vector like a plasmid. The vector then enters a host cell like a bacterium. The host reads the gene and makes the protein. The protein is then purified from cells or growth medium. Many medicines, enzymes, and vaccines are recombinant proteins.
Recombinant proteins grew out of molecular cloning in the 1970s. Before that, many proteins came from animal tissues. Supplies were limited and costly.
Many recombinant proteins carry a short added tag. A tag of six histidines grabs nickel-coated beads. This trick makes purifying the protein much easier.
Recombinant insulin now treats millions of people with diabetes. Industrial enzymes for detergents and foods are often recombinant. Researchers also use recombinant proteins to study structure and function.
The FDA approved Humulin in October 1982. It was recombinant human insulin. Eli Lilly produced it using engineered Escherichia coli bacteria. The review took only five months. The average FDA review then took 30.5 months.
Many people assume recombinant insulin differs from the human hormone. It actually has the same amino acid sequence. Insulin from pigs (Sus scrofa) differs by one amino acid. Beef insulin differs by three.
Cheesemakers once took chymosin only from calf stomachs. Cattle (Bos taurus) supplied the gene for recombinant chymosin. Yeast and fungi now produce the identical enzyme. The FDA approved it in 1990. Over 80 percent of North American cheese now uses it.
History of Biotechnology →Reporter Gene
/ reh-POR-ter jeen / · Old French reporter, to bring back; Greek genea
Reporter Gene reporter gene is a gene encoding an easily detectable protein that is fused to or placed under control of a regulatory element of interest to monitor gene expression, protein localization, or promoter activity.
Common reporters include green fluorescent protein and its variants for live imaging, luciferase for bioluminescence assays, beta-galactosidase for histochemical staining, and alkaline phosphatase for enzyme-linked detection. Reporter genes enable real-time visualization of gene expression dynamics in living cells and organisms and are indispensable tools and are used across cell biology, developmental biology, and drug discovery. CRISPR-based endogenous tagging allows reporters to be inserted at the native genomic locus of any gene.
A reporter gene makes a signal that is easy to detect. It helps scientists see when or where a regulatory sequence is active.
Reporter genes report by sending information like a sensor with a screen. They produce measurable products such as light, color, or fluorescence.
Green fluorescent protein can be used as a reporter gene in living cells. Cells expressing the reporter glow green under the right light.
Restriction Fragment Length Polymorphism
/ reh-STRIK-shun FRAG-ment LENGTH pol-ih-MOR-fizm / · Latin restrictio; Latin fragmentum; Greek polymorphos, many forms
Restriction Fragment Length Polymorphism restriction fragment length polymorphism is a variation in the length of DNA fragments produced by restriction enzyme digestion at a specific locus, used as a genetic marker for mapping and identification.
RFLPs arise when a mutation creates or destroys a restriction enzyme recognition site, or when a variable number of tandem repeats alters fragment size between alleles. Detected by Southern blotting with labeled probes, RFLPs were the first widely used co-dominant DNA markers for genetic linkage analysis and forensic identity testing. They have largely been replaced by PCR-based markers such as STRs and SNPs, which are faster, more informative, and require less DNA.
RFLPs are DNA length differences revealed after restriction enzyme cutting. They were important genetic markers before modern sequencing became common.
Are Enzymes Proteins? →RFLP analysis reads every DNA base. It detects fragment size differences caused by sequence variation at restriction sites or nearby regions.
Early genetic mapping used RFLP markers to track inheritance of chromosome regions in families. Fragment patterns helped link markers to disease genes.