106. Protein Fingerprinting (Exp-106)
Serum proteins from cow (lanes 1, 5), sheep (lanes 2, 6), goat (lanes 3, 7), and horse (lanes 4, 8) were separated by electrophoresis. The different forms of lactate dehydrogenase were then detected by activity staining.
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A comparison of specific proteins from different species provides a powerful approach for establishing evolutionary relationships and for identifying organisms. A common approach used for this purpose is protein fingerprinting where electrophoretic properties of specific proteins are analyzed in different species. In this exercise, students use the approach to compare the forms of the enzyme lactate dehydrogenase that are found in serum of different mammals. Typical results of this graphic experiment are shown below. The results illustrate that each species has a characteristic pattern of bands and that the pattern in sheep and goat is similar while the patterns from cow and especially horse are distinct.