enzyme based sequencers- typically, in manual sequencing, four reactions are set up, one for each of the four dideoxy chain terminators to be used. In addition, either the primer, used to start the reaction, or one of the normal deoxynucleotides, is labelled; this could be through a radioactive atom or through a fluorescent tag. The dideoxynucleotide is present at a concentration about 200-fold less than its competing nucleotide. There is therefore a competition between deoxynucleotides and dideoxynucleotides (eg. in animation below for dA and ddA) for incorporation into the growing chain leading to a statistical representation of lengths of DNA which correspond to the first 200-500 residues complementary to the template. Four separate reactions are run and these are loaded and their components separated within four separate lanes of a denaturing gel by electrophoresis. Labelled bands will appear at each location where the dideoxynucleotide brought that particular elongation reactions to a halt. Thus, one can read the sequence directly eg. from the autoradiograph, from the bottom to the top.
nanopore based sequences- Nanopore-based DNA analysis techniques are being industrially developed by Oxford Nanopore Technologies (developing strand sequencing using protein nanopores, and solid-state sequencing through internal R&D and collaborations with academic institutions).
Real time based sequencing- Single molecule real time sequencing (SMRT) is a parallelized single molecule DNA sequencing method. Single molecule real time sequencing utilizes a zero-mode waveguide (ZMW).[1] A single DNA polymerase enzyme is affixed at the bottom of a ZMW with a single molecule of DNA as a template. The ZMW is a structure that creates an illuminated observation volume that is small enough to observe only a single nucleotide of DNA being incorporated by DNA polymerase. Each of the four DNA bases is attached to one of four different fluorescent dyes. When a nucleotide is incorporated by the DNA polymerase, the fluorescent tag is cleaved off and diffuses out of the observation area of the ZMW where its fluorescence is no longer observable. A detector detects the fluorescent signal of the nucleotide incorporation, and the base call is made according to the corresponding fluorescence of the dye.[2]
Biotechnology- the exploitation of biological processes for industrial and other purposes, especially the genetic manipulation of microorganisms for the production of antibiotics, hormones, etc.
vaccine development- Vaccine development is a complex multistep process. ■ From concept to licensure, it takes many years to develop a vaccine. ... Safety is a major issue for any vaccine; it is assessed at every step of vaccine development and safety surveillance continues indefinitely after licensure.