A Metabolic Murder Mystery: A Case-Based Experiment for the Undergraduate Biochemistry Laboratory

Abstract

In 1990, a woman was wrongly convicted of poisoning her infant son and was sentenced to life in prison. Her conviction was based on laboratory work that wrongly identified ethylene glycol as present in her son’s blood and in the formula he drank prior to his death. The actual cause of the infant’s death, a metabolic disease, was eventually disclosed as a result of analytical work done by scientists who believed the mother was wrongly convicted. On the basis of the scientists’ work, the conviction was overturned. This real-life case serves as the launching point for a biochemistry laboratory experiment, which uses polymerase chain reaction. Students design their own primers, amplify two biological samples, and analyze the results by gel electrophoresis to determine if their patient has a genetic mutation. This genetic mutation causes the metabolic disease, which if present can be used to “solve” the case.

Environmental regulation of plant gene expression: An RT‐qPCR laboratory project for an upper‐level undergraduate biochemistry or molecular biology course

“…Students could devise their own procedure, based on the project described here, to investigate whether there is a correlation in these three parameters in additional ecotypes, as well. Note that flowering time in Arabidopsis plants is commonly measured as the developmental age at flowering, determined by counting the number of leaves once the plant has bolted .…”

“…Control samples containing no RT are prepared in parallel to assess contamination due to genomic DNA. 5 All "1RT" and "2RT" samples are stored at 220 C until laboratory Period 3. Reverse transcription does not typically require three full laboratory hours.…”

“…This is accomplished by calculating the minimum and maximum RQ values (RQ min and RQ max ) according to Eqs. (5) and (6), respectively [16]. Figure 3B shows a graphical representation of the student results from Table II.…”

“…Students could devise their own procedure, based on the project described here, to investigate whether there is a correlation in these three parameters in additional ecotypes, as well. Note that flowering time in Arabidopsis plants is commonly measured as the developmental age at flowering, determined by counting the number of leaves once the plant has bolted [5]. The project described here could also initiate a number of "open inquiry" research projects, where students develop both a problem to investigate and an appropriate procedure to investigate the problem [27].…”

“…While numerous published laboratory experiments introduce undergraduate students to “real time” qPCR (for examples, see Refs. ), a recent search of the literature found only one published undergraduate experiment employing RT‐qPCR to analyze the differential expression of a target gene . In this RT‐qPCR project described by Hancock and coworkers, students measure the expression of four target sequences during the DMSO‐induced differentiation of cultured erythrocytes.…”