Applications of Biotechnology

Saccharomyces cerevisiae

Step 1: The recombinant Hepatitis B vaccine is a subunit vaccine that uses the Hepatitis B surface antigen (HBsAg). Step 2: The gene for HBsAg is inserted into a plasmid and cloned in Saccharomyces cerevisiae (baker's yeast). Step 3: Yeast is preferred over E. coli for this purpose because yeast has the machinery for glycosylation (adding sugar groups) of proteins, which E. coli lacks. Step 4: Thermus aquaticus is the bacterium from which Taq DNA polymerase (used in PCR) is isolated — it is not used for vaccine production. Step 5: This vaccine was launched in 1997 and marketed under trade name

Adenosine deaminase deficiency (SCID)

Step 1: Gene therapy involves inserting a normal, functional gene into a person's cells to correct a genetic defect. Step 2: The first clinical gene therapy was given in 1990 by French Anderson to a four-year-old girl. Step 3: The child was suffering from Adenosine Deaminase (ADA) deficiency, also called SCID (Severe Combined Immunodeficiency). Step 4: In SCID, the T-lymphocytes do not function properly, making the patient unable to fight infections. Step 5: The therapy involved taking the patient's lymphocytes, introducing ADA cDNA using a retrovirus, and returning the engineered cells to the

Embryonic stem cells

Step 1: There are two main types of stem cells in mammals — Embryonic Stem (ES) cells and Adult stem cells. Step 2: Embryonic Stem (ES) cells are isolated from the epiblast tissue of the inner cell mass of a blastocyst (an early stage embryo). Step 3: ES cells are pluripotent — they can differentiate into cells from all three primary germ layers (ectoderm, mesoderm, endoderm). Step 4: When stimulated, ES cells can develop into more than 200 different cell types of the adult body. Step 5: Adult stem cells (also called somatic stem cells) are found in tissues of children and adults and are mostl

1971

Step 1: ELISA stands for Enzyme Linked Immunosorbent Assay. Step 2: It is a biochemical diagnostic procedure used to detect specific antibodies or antigens in a sample like serum or urine. Step 3: ELISA was discovered by Eva Engvall and Peter Perlmann in 1971. Step 4: The other years are linked to different discoveries — 1957 was when interferons were discovered, 1983 was when PCR was developed by Kary Mullis, and 1990 was when the first gene therapy was performed. Step 5: ELISA is commonly used to test if a person is HIV positive or negative and can detect antigens in the range of a nanogram,