Biotechnology

Biotechnology

A Little History •

1953: DNA is first described by Watson and Crick.

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1973: Cohen and Boyer develop genetic engineering techniques to "cut and paste" DNA and reproduce the new DNA in bacteria.

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1978: Genentech scientists and their collaborators produce recombinant human insulin.

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1983: Polymerase chain reaction (PCR) technique conceived (will become a major means of copying genes and gene fragments).

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1990: Human Genome Project (HGP), an international effort to map all the genes in the human body, is launched.

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2000: First draft of human genome sequence completed by the HGP and Celera Genomics.

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2007: Two additional human genomes were completed for a total of three

Cumulative Pace of Disease Gene Discovery 1981-2005 2000 1800 1600 Number of Genes Associated with Disease

1400 1200 1000 800 600 400 200 0 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

Year Source: Online Mendelian Inheritance in Man

Step 1 • Isolate what you want to study (DNA or protein).

Isolating Cellular Components • Cell Fractionation – Cells are broken down and separated by density – Further separation can be achieved through various chemical methods

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Step 2 • Concentrate enough of what you want to study. OR • Make more of it

PCR • Polymerase Chain Reaction

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How many strands of DNA would 25 cycles yield?

DNA Sequencing and the Human Genome • The human genome was first sequenced in 2000. • Humans have 20-25,000 genes (a surprisingly low number -- corn plants have 50,000 for example).

• Individual humans differ by about 250300 genes at most. 15.7

Step 3 • Analyze what you are studying. – Size and sequence are two common ways to analyze DNA

• DNA has a negative charge

Gel Electrophoresis

• It moves toward the positive anode • Smaller particles move faster

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Step 4 • Use the molecule you are studying in a new system to see how it works or to make a product.

Restriction Enzymes • Cut DNA at a specific location

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RFLP Analysis • Restriction Fragment Length Polymorphism • Because DNA differs in sequence, restriction enzymes will produce fragments of different lengths.

DNA Fingerprinting Using Restriction Enzymes

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OJ Simpson Trial • Odds of seeing 3 albino deer at the  same time:

85 million to 1 • Odds of the blood on the glove not  being from R. Goldman, N. Brown­ Simpson, and O.J. Simpson:

21.5 billion to 1

Recombinant DNA and Cloning Genes

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Recombinant DNA and Cloning Genes

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Practical Uses of DNA Technology • Diagnosis of disease • Human gene therapy • Pharmaceutical products (vaccines) • Forensics • Animal husbandry (transgenic organisms) • Genetic engineering in plants • Ethical concerns?

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