Organelle Isolation and Marker Enzyme Assay

 

Tested Studies in Laboratory Teaching, 1992, Volume 13

Abstract

Cells contain many specialized structures known as organelles which perform a variety of specific functions. To obtain precise information about the structure and functions of subcellular organelles, it is imperative to isolate them free from contaminating organelles. Marker enzymes are known to be localized exclusively in specific organelles and are used to monitor the separation of these organelles. In this exercise the homogenate of Dictyostelium discoideum will be fractionated by differential centrifugation to separate mitochondria, lysosomes, and contractile vacuoles. The fractions will be assayed for their marker enzymes: acid phosphatase for lysosomes, succinate dehydrogenase for mitochondria, and alkaline phosphodiesterase for the contractile vacuoles. This exercise presents two fundamental concepts to the students: organelle isolation and enzyme assays.

Keywords:  mitochondria, organelles, marker enzyme, Dictyostelium discoideum, enzyme assay, lysosome, contractile vacuole

University of Wyoming, Laramie (1991)