Collaborations between and within sectors are common and crucial to the creation and transfer of knowledge. It is often unclear who is involved in the collaboration, and with whom and why they are collaborating. I studied reasons for collaboration and how capital and institutions affect collaboration through a mixed methods analysis of infection and immunity research and development collaborations in Vancouver, Canada between individuals affiliated with universities, firms, and health-care organizations. I found that both capital and institutions were important in collaboration decisions. Collaboration worked as a balancing act between capital and institutions. Potential collaborators needed to offer different capital to the collaboration while supporting the dominant institutions of potential collaborators. Participants' organizational and sectoral affiliations influenced available capital and dominant institutions. These findings help policy makers understand collaboration dynamics between sectors and how translation can occur between universities, firms, and health-care organizations.