Data standards for flow cytometry.

Flow cytometry (FCM) is an analytical tool widely used for cancer and HIV/AIDS research, and treatment, stem cell manipulation and detecting microorganisms in environmental samples. Current data standards do not capture the full scope of FCM experiments and there is a demand for software tools that can assist in the exploration and analysis of large FCM datasets. We are implementing a standardized approach to capturing, analyzing, and disseminating FCM data that will facilitate both more complex analyses and analysis of datasets that could not previously be efficiently studied. Initial work has focused on developing a community-based guideline for recording and reporting the details of FCM experiments. Open source software tools that implement this standard are being created, with an emphasis on facilitating reproducible and extensible data analyses. As well, tools for electronic collaboration will assist the integrated access and comprehension of experiments to empower users to collaborate on FCM analyses. This coordinated, joint development of bioinformatics standards and software tools for FCM data analysis has the potential to greatly facilitate both basic and clinical research--impacting a notably diverse range of medical and environmental research areas.

The use of the BD oxygen biosensor system to assess isolated human islets of langerhans: oxygen consumption as a potential measure of islet potency.

The measurement of cellular oxygen consumption rate (OCR) is a potential tool for the assessment of metabolic potency of isolated islets of Langerhans prior to clinical transplantation. We used a commercially available 96-well plate fluoroprobe, the BD Oxygen Biosensor System (OBS), to estimate OCR in 27 human islet preparations, and compared these results to those of concurrent mouse transplantations. OCR was estimated both from the dO2 at steady state and from the transient rate of change of dO2 during the initial culture period immediately after seeding ("dO2 slope"). To demonstrate the validity of the OBS-derived values, it was shown that they scaled linearly with islet equivalent number/DNA concentration and with each other. These measurements were obtained for each preparation of islets incubated in media supplemented with either low (2.2 mM) or high (22 mM) glucose. Concurrently, one to three athymic nude mice were transplanted with 2,000 IEQs under the kidney capsule. The OCR Index, defined as the ratio of the DNA-normalized "dO2 slope" in high glucose to that in low glucose, proved highly predictive of mouse transplant results. Of the 69 mice transplanted, those receiving islets where the OCR Index exceeded 1.27 were 90% likely to reverse within 3 days, whereas those receiving islets with an OCR Index below 1.27 took significantly longer, often failing to reverse at all over a 35-day time period. These results suggest that the OBS could be a useful tool for the pretransplant assessment of islet cell potency.