Electrophoresis is a powerful tool for separating proteins in complex mixtures. However, it is often necessary to identify specific enzymes and structural proteins after electrophoresis so they can be studied in further detail. In this series of experiments, students use electrophoresis in conjunction with novel immunological and enzymatic procedures to study tissue-specific proteins in animals and plants. As in all of our programs, enough materials for 8 groups of students are included. Sufficient materials are provided so that experiments 803 and 804 can be preformed twice: once with the tissues provided with the program and once with tissues of your choice. The PROCELL Electrophoresis Unit, a tabletop centrifuge, and a 37°C waterbath are required.

Western blotting is one of the most powerful methods in molecular biology for identifying and characterizing specific proteins in complex protein mixtures. We have now streamlined western-blotting procedures so that the entire analysis can be performed during a single 3-hour, or two 2-hour laboratory sessions. In exercise 801, students use the procedure outlined below to identify albumin, transferrin and gamma globulins in serum and then to study the evolutionary relationships of albumin in vertebrates.

Chicken egg white contains a variety of proteins including ovalbumin, conalbumin, ovomucoid and lysozyme. In this exercise, students use the western press-blot procedure to characterize chicken ovalbumin and then to determine if the protein is found in egg whites from turkey and quail.

Isoenzymes are different molecular forms of the same enzyme and five major lactate dehydrogenase (LDH) isoenzymes are found in vertebrate tissues. The amounts of the isoenzymes vary in a tissue specific manner and these differences can be readily detected by localizing LDH activity in an agarose gel after electrophoresis of tissue extracts. In this exercise, students prepare a tissue extract from calf thymus and then compare the LDH isoenzyme profile to those from calf serum, heart and muscle.

Peroxidase is associated with the plant cell wall and different forms of peroxidase are found in different plant tissues. These tissue-specific differences are revealed by this exercise where students examine the electrophoretic patterns of peroxidase in corn root and shoot extracts.

Individual Experiments