and Abstract This proposal by the Scripps Research Institute is aimed at purchasing a Biomark instrument from Fluidigm. This instrument will be dedicated to studying single cells at the transcriptional and respond to an increasing demand from the scientists of TSRI. The Institute is committed to fully support this application that stems from the Department of Immunology and Microbial Science. The necessary resources and personnel needed for operation will committed through housing the new instrument within the DNA Core of TSRI under the supervision of the Core director, Steven Head. Our request for a Biomark machine is motivated by the urgent need to bring to our institution a new technology that will allow experiments that cannot currently be carried out on-site and that will add to the quality of our output. This microfluidic machine has the huge advantage of versatility as it can be used for real-time PCR, digital PCR, genotyping, and sequencing. With respect to single cell analysis, we could not find comparable pieces of equipment from any of the competitive genomics hardware companies. In immunology, the need to study single cells has exploded over the past few years as the community has now realized of the heterogeneity of cell populations. This new way of looking at the immune response has been greatly facilitated by our capacity to isolate specific single B and T cells by fluorescence activated cell sorting using labeled antigens and labeled MHC multimers, respectively. The current hurdle is the limited ability that we have to extract multiparametric information from the isolated single cell. Similarly, neurobiologists want to interrogate single neurons and cancer biologist want to examine tumor heterogeneity. The instrument will be housed in and operated by the TSRI DNA Core Facility. For immunological applications the entire collection of primers will be available at cost to investigators. Indeed, te collection of primer sets needed for immunological applications is very standardized in both mouse and man and can be easily categorized. As a core instrument, the Biomark will be available to all investigators on campus under the supervision of the core director and its advisory committee. The core will be capable of providing basic training although formal manufacturer training will be highly encouraged before using the instrument. Booking will be on-line and under the supervision of the core director. The instrument will be under a maintenance contract paid by a cost-recovery program.