Implementing Research Shared (Core) Facility Billing Systems.

Research Shared (core) Facilities (RSF) operate as centers of expertise and help to accelerate basic and translational science. A centralized platform for unified ordering, equipment reservation, and the billing of services using an integrated software system is a valuable resource that many academic institutions should consider. This paper discusses considerations for best practices and identifies lessons learned from the implementation of two different software systems for RSF. After implementing two different centralized billing systems for RSF, this paper identifies considerations for best practices and discusses lessons learned.

Separation by cell size enriches for mammary stem cell repopulation activity.

Mammary gland reconstitution experiments, as well as lineage tracing experiments, have provided evidence for the existence of adult mammary stem cells (MaSCs). In addition, cell sorting techniques for specific cell surface markers (CD24(+)CD29(H)CD49f(H)Sca1(-)) have been used to prospectively isolate MaSC-enriched populations. Although these markers enrich for cell subpopulations that harbor MaSCs, they do not identify regenerative stem cells uniquely. Here, we report that MaSCs can be further defined by the property of cell size. Fluorescence-activated cell sorting was used to analyze sizing beads and further separate populations of cells with varying degrees of forward scatter (FSC). Cells with a low FSC that were approximately <10 µm in size lacked outgrowth potential and failed to reconstitute the mammary gland when transplanted into the cleared fat pads of syngeneic mice. In contrast, cells >10 µm in size with a higher FSC had increased outgrowth potential as compared with lineage-negative (LIN(-)) control cells. Limiting dilution transplantation assays indicated that the repopulating ability of LIN(-)CD24(+)CD29(H) cells that were >10 µm in size was significantly increased as compared with cells marked by CD24 and CD29 alone. These results suggest that MaSCs can be further isolated by sorting based on size/FSC. These findings have critical implications for understanding mammary gland stem cell biology, an important requisite step for understanding the etiology of breast cancer.