Determination of the molecular weight and size of proteins in solution: assessment of an educational innovation.

WANDA M. VALSECCHI; SANTIAGO E. FARAJ

Buenos Aires

Congreso; Biofísica en tiempos de COVID-19 - Primeras Jornadas Virtuales de la Sociedad Argentina de Biofísica.; 2020

Sociedad Argentina de Biofísica

The calls to improve student learning and to increase the number of STEM graduates affirm the need for widespread adoption of evidence-based teaching practices. This study describes how challenging students with a focused practical activity results in significant knowledge and skills development. Our goal was to promote further understanding of size exclusion chromatography (SEC) and light scattering (LS) by making students face real-life dilemmas when trying to determine the size and molecular weight of proteins in solution. The activity allowed them to have first-hand evidence of the advantages and limitations of different available techniques, and to realize that determinations by SEC may be misleading for certain challenging proteins.Here we report findings from an educational study performed during the 2018 and 2019 offerings of two graduate-level courses that deal with methods on protein chemistry, structure, and interactions. We collected information on perceived and actual learning gains through pre- and post-tests, and by analyzing lab reports performance.The assessment of the implementation showed that students managed to process SEC and LS data and to explain experimental observations. Students confront the fact that protein samples may not be pure or simple in nature and may have anomalous hydrodynamic behaviours, and understand to which extent each technique is appropriate to solve a given problem. Our results indicate that the practical innovation we propose is a challenging activity that successfully promotes the development of core concepts and competencies. Besides, our findings highlight the importance of reinforcing data analysis components of laboratory practical activities.