Chapter 2. Molecular Biology II

General Purpose

This pre-lab will present some of the general concepts related to some of the techniques used in the fields of microbiology and molecular biology and how these techniques relate to understanding the relationship between DNA, genes, and traits expressed by an organism.

Learning Objectives

General Purpose

• Develop a basic understanding of some of the techniques used in the field of molecular biology.

Procedural

• Gain proficiency in analyzing plasmid maps.

Background Information

There are two related parts of analyzing plasmid maps. The first part is determining the number of cuts in the plasmid. In Figure 12-2 is a plasmid map.

Figure 12-2. Plasmid map showing the positions of the restriction enzyme cut sites.

From this plasmid map you can count three EcoRI restriction sites. Therefore, cutting this plasmid with EcoRI will yield three fragments.

The second part of the analysis is determining the sizes of the fragments that will be generated by digestion with a restriction enzyme. The total size of the plasmid shown in Figure 12-2 is 5186 bp. That means the total size of the three fragments will add up to 5186 bp. To determine the individual fragment sizes use the positions of the individual cut sites. There is a cut site at position 3054 and another cut site at position 2011. Therefore, the fragment that would be generated by a restriction enzyme cutting at those sites would be 1043 bp.

Pre-Lab Quiz

Proceed to the Pre-Lab Quiz