General Purpose
Conceptual
Procedural
This lab will help familiarize you with some of the techniques you will be using in the exercises throughout this manual. It will also introduce you to some of the basic equipment needed to conduct the exercises in the manual.
Conducting experiments in biology requires the use of certain specialized equipment and techniques. To perform these techniques and use this equipment accurately and efficiently it is important to understand how the equipment works and to become practiced in the techniques. One of these techniques is spectrophotometry. The spectrophotometric techniques you are going to use during this exercise will be used during many of the other laboratory exercises this semester, and you may use them in other courses in the future. These techniques are also used in a wide variety of fields from industry to health care.
Spectrophotometers are one of the most widely used laboratory instruments. Before continuing on, please read Appendix A, which describes the basic operation and use of a spectrophotometer in more detail. Cobalt chloride (CoCl2) solution is colored and follows Beer’s law: When monochromatic radiation passes through a medium (e.g., solution) containing an absorbing substance, the decrease in the intensity of the light which is transmitted (or the increase in the intensity of the light absorbed) by the substance is directly proportional to the concentration of absorbing species. In other words, as the concentration of a substance in solution increases, the amount of light absorbed by the solution increases. We can use a spectrophotometer to measure the concentration of CoCl2 in a solution as a function of the absorbance.
Proceed to the Pre-Lab Quiz