Written by: The Midland Certified Reagent Company
Summary: Learn more about the synthetic oligonucleotides used for research purposes.
There are a number of modifications and labels for synthetic oligonucleotides commonly used by scientists for genetic research purposes. Custom 3’ or 5’ and internal modifications are available for laboratory or pharmaceutical research involving DNA synthesis.
Each modified oligo is a fundamental building block of DNA used very commonly in polymerase chain reactions. Modifications are completed at the time of synthesis, and range from fluorescent tagging on dual-labeled probes to purification.
Modified oligos are crucial to the processes of artificial DNA synthesis, fluorescent in situ hybridization (FISH), and many more. They have many practical applications in medicine, research, forensic science, and genetic analysis and testing.
A fluorescent label is a simple modification used on dual-labeled probes that aids with the detection and localization of specific targets, most commonly a 
biomolecule such as a protein, antibody, or amino acid.
Fluorescent proteins were introduced in the early 1990s, and since then, continuous advancements in cell imaging have paved the way to more effective identification of viruses, bacteria, and tumors.
Oligos can be purified through electrophoresis. Some common purification modalities include HPLC and PAGE purification, although technology has advanced far enough in recent years that many genes require less purification than in the past.
This is by no means a comprehensive list of modifications. There are over three hundred different types available for DNA, RNA, and LNA synthesis. Time and time again, modifications have been proven successful in the process of DNA synthesis, and the evidence is available in each MALDI-TOF mass spectrum printout.