Life Sciences 3 Introduction to Molecular Biology
Lab Modules - Concepts and Skills
LAB 1 - Pipetter Exercise & Analysis of Protein Size Using SDS-PAGE  
In this lab students are going to get to know the most commonly used instrument in molecular biology – the micropipetter. Students will learn the proper procedure for operating pipetters during this exercise. Then they use the pipetters to conduct an SDS-PAGE experiment. One of the basic ways to understand a protein is to know its mass. There are a few methods to learn the mass of a protein. In this exercise students will use gel electrophoresis to estimate the mass of the subunits of an unknown protein. In conjunction with information gathered from other methods, the number of subunits of the unknown protein also will be determined.
  Concepts –  
  Understanding protein structure  
  Understanding protein size estimation methods  
  Skills –  
  Proper use of micropipetters   
  Loading an SDS-PAGE gel   
  Creating a standard curve in Excel  
  Determining the size of an unknown polypeptide using a standard curve  
   
LAB 2 - Biochemical Assay of β-Galactosidase Activity  
Beta-galactosidase is an enzyme that breaks down lactose into two monosaccharides. Students will learn to measure the activity of the enzyme by measuring the rate at which products appear and the time required for this enzyme to be synthesized.
  Concepts –  
  Understanding the lac operon and its function  
  Using an assay to indirectly calculate enzymatic activity  
  Skills –  
  Proper use of micropipetters  
  Correct handling and disposal of bacterial cells  
  Use of the spectrophotometer, including using the correct blank  
   
LAB 3 - DNA Isolation & Amplification  
Polymerase chain Reaction (PCR) is a technique that allows scientists to make many copies of DNA from a small sample. In this lab, students will isolate DNA from cheek cells and prepare the sample for PCR. The samples will be amplified and sent out for sequencing for use in lab 5. Good primer design is a vital part of developing a PCR protocol, so students will be asked to practice creating a primer pair in the primer design exercise.
  Concepts –  
  Primer design (by hand and using Primer-3)  
  Mitochondria and maternal lineage  
  PCR for DNA amplification  
  How primers work  
  5' to 3'  
  Skills –  
  Proper use of micro-pipetters  
  Chelex extraction of DNA from cheek cells  
  Use BLAST to check primer uniqueness  
   
LAB 4 - Agarose Gel Electrophoresis & Molecular Clocks  
In this lab students will receive a portion of your amplified DNA sample from lab 3. They will check for PCR product in two ways: by visualizing the product on an agarose gel and by checking the concentration using the spectrophotometer. Students also will learn how to use BLAST, ClustalX and Mega4, programs to be used in the analysis of individual sequences in lab 5.
  Concepts –  
  Understand qualitative and quantitative measures of PCR success  
  Understand MCRA and how to read phylogenetic trees  
  Understand the concept of the molecular clock  
  Skills –  
  Proper use of micropipetters  
  Load and run an agarose gel  
  Use the spectrophometer to determine DNA concentration  
  Use BLAST to align two DNA sequences  
  Estimate a divergence rate for a set of sequences  
  Align multiple DNA sequences in ClustalX  
  Draw a phylogenetic tree in Mega4  
   
LAB 5 - Sequence Analysis and Maternal Lineages  
In this lab students will receive their mitochondrial DNA sequence, which was sequenced off site after the PCR amplification. Students will compare it to many other sequences, an analysis that will allow them to determine their maternal lineage based on human migration patterns. Students will annotate their sequence and re-visit the programs used in lab 4 to create phylogenetic trees with their own sequence.
  Concepts –  
  Understand dideoxy sequencing method  
  Understand human migration patterns and haplogroups  
  Interpret data obtained from BLAST  
  Interpret a phylogenetic tree  
  Skills –  
  Use Chromas to clean up a DNA sequence  
  Use BLAST to search for a haplogroup  
  Annotate a sequence  
  Align sequences in ClustalX  
  Draw a phylogenetic tree using Mega4  
   
LS Laboratory Website  
  Information on class, section and room schedule can be found here:  
  http://lslab.lscore.ucla.edu