Virtual protein quantification laboratory enhancing online teaching

The interruption of classes caused by the COVID pandemic, dictated a need for alternative online solutions to practical laboratory activities.^{1, 2} In this regard simulations and animations of laboratory procedures may be useful.

Laboratory simulations offer flexibility to learners through multiple, self-paced, repetitions. Student laboratory time allocated to equipment manipulations may be reorganized to interpretation and discussion of results. In addition, despite the fact that simulations cannot replace the whole laboratory experience, realistic simulations can partially convey to the students the experience of being in a laboratory.

This online laboratory activity simulates the determination of protein concentration in unknown samples, an experiment integrated in biochemistry curricula internationally. The learning goals defined are related to understanding the concepts of protein, colorimetric reactions, spectrophotometry, linear regression; understanding the scientific method/experimental model; apply theoretical knowledge in problem solving; develop the ability to analyze experimental data. The activity focuses on laboratory techniques and skills listed in the matrix for development and assessment of undergraduate Biochemistry and Molecular Biology laboratory programs.³

The activity uses the Flash application ProtVirt⁴ and simulates the biuret Protein Assay and protein determination by visible light spectrophotometry. This activity is primarily targeted at introductory biochemistry courses. This activity is primarily targeted at first- or second-year general biochemistry courses that introduce students to protein structure and function.

The sections in the ProtVirt help to understand the main concepts with texts and animations to perform the virtual experiment and in the real afterwards.

The simulation guides the user through the steps of the process. Students interact with virtual equipment to perform protein quantification, from reagent preparation (video demonstration) to performing the spectrophotometrical measurements—clicking on arrow buttons to advance through subsequent steps. It is necessary to turn on the equipment, carry out the configurations, and insert the samples in the device to perform the readings.

It is noteworthy that the software issues alert on the screen for some common errors, such as absence of a blank, or measuring with the open device, or even without the cuvette.

After obtaining the absorbances, students enter data obtained with the simulation in a spreadsheet application to obtain colorimetric standard curves and calculate the protein concentrations in the unknown samples.

The teacher must indicate the environment where they will insert the results (graph and calculations) and encourage discussion in a forum with questions like:

The use of this virtual laboratory can, when well-integrated with the subject's proposal and educational objectives, assist the student in the understanding of colorimetric measurement techniques, in the context of proteins, and in the use of spectrophotometer.