Experiment on protein detection using electrophoresis for upper secondary high school biology

Practice II: Detection of tissue-specific proteins

Abstract

Teaching materials were developed for performing sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The aim of the practical was the detection of tissue-specific proteins in a large volume of differentiated animal cells. The procedures were practiced in class. Electrophoresis samples were prepared by adding a trace amount of material to the sample treatment solution. As a result of the experiment, I demonstrated that myosin heavy chain, actin from muscle tissue, and hemoglobin from blood or bone marrow could be detected in pigs, chickens, and horse mackerel. Molecular groups of crystalline proteins from the lens could be detected in tissues of pigs and horse mackerel. In pigs, by separating blood into serum and cells, I confirmed that serum albumin is present in blood serum and hemoglobin is present in blood cells. Pigs are considered a suitable experimental subject, and students performed experiments using pig tissues in class. Preparation of gels used for SDS-PAGE is very easy for teachers because precast gel is readily available from stores. When this experiment was conducted, students were encouraged to investigate the amount and molecular weight of each protein by themselves as much as possible. From experimental results, students easily estimated the types of proteins in the major bands on electrophoretograms. Moreover, by combining SDS-PAGE with microscopic observation of muscle and blood, students were able to better understand the locations of proteins detected in the tissues.