Microsomes Protocol

The liver plays a major function in the transformation of drugs in the body. Microsomes are subcelluar fractions of liver tissue. Specific procedures called protocols are needed for researchers to study microsomes, enzymes and drug interactions.

Basic Protocol

• The protocol involves adding compounds to microsomes with and without an electron carrier. Samples are taken at predetermined times and centrifuged. The results with and without the electron carrier are compared.

Variation in Centrifugation

• While the major elements of the protocol may remain the same, variations in some steps result in improved outcomes. The results are compared to revise the protocol. In one case the force of centrifugation was varied. Results indicated that by reducing the force, the purity of microsomes was increased.

Variation in Buffer Solutions

• The liver cells are generally diluted with a buffer solution in a step known as homogenization. One avenue of research has been the presence and absence of sucrose in the solution. Results indicate that when sucrose is present, reductuase activity increases, according to studies done by the Center for Human Toxicology, Department of Pharmacology and Toxicology at the University of Utah. Reductase is an enzyme that serves to catalyze organic reactions by reducing the required activation energy.

Variations in Homogenization

• The mixing of the cells with a buffer solution is accomplished by shaking the solution and cells in a tube by hand. When ten strokes to mix the solution are used instead of six or eight, reductuase activity increases.