Abstract
Here, we present a protocol for 3D printing heart tissues using thiol-norbornene photoclick collagen (NorCol). We describe steps for synthesizing NorCol, preparing bioink and the support bath, and cell-laden printing. We then detail procedures for the loading of C2C12 cells into NorCol, ensuring structural integrity and cell viability after printing. This protocol is adaptable to various cell lines and allows for the printing of diverse complex structures, which can be used in drug screening and disease modeling.