Biol 1440, Principles of Biology I

Basic Lab Skills

To prepare you for conducting an experiment to test a hypothesis on the effects of alcohol on cell membranes, this lab is designed to teach some basic laboratory skills on how to make dilutions and to calculate concentrations from Absorbance using the Lambert-Beer Law.




  • Learn how to make dilutions using the mass-balance equation
  • Learn how to use pipettes in preparing dilutions
  • Learn about the relationship between Absorbance and concentration using the Beer-Lambert Law

Student Checklist


  • Calculator
  • Graph paper or lab notebook, 
    Ask your instructor which is required
  • Marking pen

Directed Investigation

Developing Skills
Each student will learn how to make dilutions.  You will use these techniques in other labs.

Review the metric system- molarity and volume.  Practice Quiz

1.  Graphing- Review of how to make a graph and interpret it.

2.  Instructors will demonstrate how to pipette solutions for making dilutions. 

3.  How to use a spectrophotometer.

4.  Calculating concentration using the Lambert-Beer formula.

5.  Making dilutions using the mass-balance equation  [Review Mass BalanceNEW!!  Mass-Balance - a visual guide (pdf)

6. Constructing a dilution table