Kilimanjaro Christian Medical University College 1 article published in JoVE Medicine In Vitro Assessment of Cardiac Function Using Skinned Cardiomyocytes Patrícia Gonçalves-Rodrigues*1, João Almeida-Coelho*1, Alexandre Gonçalves1, Flávio Amorim1, Adelino F. Leite-Moreira1, Ger J.M. Stienen2, Inês Falcão-Pires1 1Unidade de Investigação Cardiovascular, Departamento de Cirurgia e Fisiologia, Faculdade de Medicina, Universidade do Porto, 2Department of Physiology, Kilimanjaro Christian Medical University College This protocol aims to describe step-by-step the technique of extraction and assessment of cardiac function using skinned cardiomyocytes. This methodology allows measurement and acutemodulation of myofilament function using small frozen biopsies that can be collected from different cardiac locations, from mice to men.