Genetic Engineering and Biotechnology IB Topic 4.3

Exploring DNA DNA is at the very core of what gives animals and plants their uniqueness In this topic, we are going to look at the genetic techniques developed in the past few decades which enable scientists to explore and manipulate DNA

These include: Copying DNA in a lab Polymerase chain reaction (PCR) Using DNA to reveal its owner’s identity DNA profiling Mapping DNA by finding where every A, T, C, and G is The Human Genome Project Cutting and pasting genes to make new organisms Gene transfer Cloning cells and animals

What’s the big deal? These techniques offer (just to name a few): New hope for obtaining treatments and vaccines for diseases Creating new plants for farmers Freeing wrongly convicted people from prison

Some techniques have sparked debate & controversy Gene transfer & cloning Is it morally and ethically acceptable to manipulate nature? Is it morally and ethically acceptable to create human embryos for scientific research? Big biotech companies – helping society or out to make money?

How does this affect YOU? Part of being a responsible citizen is making informed decisions relating to difficult questions. IB learner profile It’s not just the technical complexity that makes these questions difficult, it’s also because humans have never had to face them before.

Polymerase Chain Reaction (PCR) PCR is a lab technique which takes very small quantities of DNA and copies all the nucleic acids in it to make millions of copies of the DNA

PCR PCR allows scientists to get enough DNA from a sample to be able to analyze it Collecting DNA from a crime scene or a cheek swab often have a limited number of cells to work with PCR allows scientists to makes millions of copies of the DNA in a few hours Such quantities are large enough to get results from other tests (like gel electrophoresis)

YouTube Video – PCR ko1xY&feature=relatedhttp:// ko1xY&feature=related

Gel Electrophoresis Lab technique used to separate fragments of DNA What’s the purpose? Done in effort to identify its origin

How does gel electrophoresis work? Enzymes chop up long filaments of DNA into varying sized fragments The fragments are placed into small wells (holes) in gel Aligned along one end The gel is exposed to electric current Positive on one side, negative on the other

Gel electrophoresis continued What’s the effect? The biggest, heaviest and least charged particles do not move easily through the gel They stay relatively close to the wells The smallest, least massive and most charged particles pass through the gel to the other side with little difficulty Intermediate particles are distributed in between In the end, the fragments have a banded pattern

The results … Analyzing the banding pattern can be used in DNA profiling