Development of micro-well array systems for use in high-throughput screening of rare cells requires a detailed understanding of the factors that impact the specific capture of cells in wells and the distribution statistics of the number of cells deposited into wells. In this study we investigate the development of microbubble (MB) well array technology for sorting antigen-specific B-cells. Using Poisson statistics we delineate the important role that the fractional area of MB well opening and the cell seeding density have on determining cell seeding distribution in wells. The unique architecture of the MB well hinders captured cells from escaping the well and provides a unique microenvironmental niche that enables media changes as needed for extended cell culture. Using cell lines and primary B and T cells isolated from human peripheral blood we demonstrate the use of affinity capture agents coated in the MB wells to enrich for the selective capture of B cells. Important differences were noted in the efficacy of bovine serum albumin to block the nonspecific adsorption of primary cells relative to cell lines as well as the efficacy of the capture coatings using mixed primary B and T cells samples. These results emphasize the importance of using primary cells in technology development and suggest the need to utilize B cell capture agents that are insensitive to cell activation. © 2013 Springer Science+Business Media New York.