Cell microencapsulation requires clinically approved materials for their use in pharmaceutical and/or biomedical applications. The overwhelming majority of the literature has used the classical alginate-poly-l-lysine-alginate (APA) capsules for cell immobilization. Although alginate is granted with the medical approval, some of the remaining components such as foetal bovine serum (FBS), an essential ingredient of cell culture media, are not in accordance with the guidelines affirmed by the American Society for Testing and Materials (ASTM) and Food and Drug Administration (FDA). In this paper, human serum albumin (HSA), a medically approved substance, was evaluated as a potential substitute of FBS. The effect of different percentages of FBS and HSA was studied on the proliferation rate, viability and protein production of two different cell lines (C2C12 and baby hamster kidney (BHK) cells), maintained in culture and immobilized in APA microcapsules. Results show that substitution of FBS by HSA reduced the functionality of both non-encapsulated and encapsulated BHK cells. However, immobilized C2C12 cells presented the highest level of viability and a reduction in protein production of 25% when 1% HSA was used. It can be concluded that HSA might be a possible substitute of FBS in order to maintain or transport encapsulated C2C12 cells for short periods of time before implantation.