Class Notes 1: DNA Manipulation

I. DNA manipulation A. During recent years, scientists have developed a technique to manipulate DNA, enabling them to study DNA and genes. B. A DNA molecule is too small for a scientist to cut themselves, so it is cut by special restriction enzymes.

II. Restriction Enzymes A. Used by bacteria to cut up DNA of viruses. B. Many different types that cut DNA at different sequences.

III. Copying DNA A. Often, DNA samples are very small. B. In order to get enough DNA to study,a polymerase chain reaction (PCR) is used to copy the same segment over and over.

IV. Separating DNA A. Gel electrophoresis separates the cut DNA by length, using an electrical current.

V. How is the DNA used? A. Genetic engineering- new genes can be added to an organisms DNA. B. Mutations and genetic diseases can be shown through different DNA fragments. C. A DNA fingerprint can identify a criminal, body, or missing person. D. DNA from different species can be compared to determine their relationship.

Summary Why are restriction enzymes used? Why is it helpful to manipulate DNA?