DNA Technology - BiologyJunction


Dec 12, 2012 (8 years and 11 months ago)


Lecture #9

Date _____

Chapter 20~

DNA Technology

& Genomics

O.J. Simpson capital murder case,1/95

Odds of blood in Ford Bronco

being R. Goldman’s:

6.5 billion to 1

Odds of blood on socks in bedroom

being N. Brown

8.5 billion to 1

Odds of blood on glove


being from R. Goldman, N. Brown
Simpson, and O.J.

21.5 billion to 1

Number of people on planet earth:

6.1 billion

Odds of being struck by lightning in the U.S.:

2.8 million to 1

Odds of winning the Illinois Big Game lottery:

76 million to 1

Odds of getting killed driving to the gas station to buy a lottery ticket

4.5 million to 1

Odds of seeing 3 albino deer at the same time:

85 million to 1

Odds of having quintuplets:

85 million to 1

Odds of being struck by a meteorite:

10 trillion to 1

Recombinant DNA


DNA in which genes
from 2 different sources
are linked

Genetic engineering:

direct manipulation of
genes for practical


manipulation of organisms
or their components to
perform practical tasks or
provide useful products

Bacterial plasmids in gene cloning

DNA Cloning

Restriction enzymes (endonucleases

in nature, these enzymes protect
bacteria from intruding DNA; they cut up the
DNA (restriction); very specific

Restriction site

recognition sequence for a particular
restriction enzyme

Restriction fragments

segments of DNA cut by restriction
enzymes in a reproducable way

Sticky end

short extensions of restriction

DNA ligase

enzyme that can join the sticky ends of
DNA fragments

Cloning vector

DNA molecule that can carry foreign
DNA into a cell and replicate there (usually
bacterial plasmids)

Restriction Enzymes

Steps for eukaryotic gene cloning

Isolation of cloning vector
(bacterial plasmid) & gene
source DNA (gene of interest)

Insertion of gene
source DNA
into the cloning vector using the
same restriction enzyme; bind
the fragmented DNA with DNA

Introduction of cloning vector
into cells (transformation by
bacterial cells)

Cloning of cells (and foreign

Identification of cell clones
carrying the gene of interest


DNA Analysis & Genomics

PCR (polymerase chain

Gel electrophoresis

Restriction fragment
analysis (RFLPs)

Southern blotting

DNA sequencing

Human genome


Polymerase chain reaction (PCR)

Amplification of any
piece of DNA without
cells (in vitro)

Materials: heat, DNA
nucleotides, single
stranded DNA primers

Applications: fossils,
forensics, prenatal
diagnosis, etc.

DNA Analysis

Gel electrophoresis
: separates nucleic acids or proteins on the
basis of size or electrical charge creating DNA bands of the
same length

Restriction fragment analysis

Restriction fragment length polymorphisms (RFLPs)

Southern blotting
: process that reveals sequences and
the RFLPs in a DNA sequence

DNA Fingerprinting

DNA Sequencing

Determination of
nucleotide sequences
(Sanger method,
sequencing machine)

Genomics: the study of
genomes based on

DNA sequences

Human Genome


Practical DNA Technology Uses

Diagnosis of disease

Human gene therapy

Pharmaceutical products


Animal husbandry
(transgenic organisms)

Genetic engineering in

Ethical concerns?