Undergraduate biology programs are currently undergoing reform to involve students in biomedical research. Engaging students in more active, hands-on experiments allows students to discover scientific principles for themselves, and to develop techniques of critical thinking and problem solving. This models the world of real scientific research, where scientists are confronted with specific problems each day, often dealing with experimental design. Critical-thinking and higher-order, reasoning skills are required to meet and overcome such challenges. A good example of this is the individual isolation of both high quality RNA and protein from the same small organ. This is difficult because of RNase degradation problems and low yields. In addition, a homogeneous sample of the tissue is needed for preparation of both components in order to obtain scientifically accurate results. This demonstration describes a procedure for overcoming these obstacles, and allows for the isolation of high quality RNA and protein to perform both Northern and Western blot techniques from the same small tissue. In this exercise, students are exposed to a demonstration detailing a specific problem of how to extract both protein and RNA from the same small tissue. This demonstration is a good example of the application of higher-order thinking skills and the critical thinking required by scientists each day in the performance of their research. (Contains 4 figures.)