Analysis of the DNA sequencing quality and efficiency of the Apollo100 robotic microcycler in a core facility setting.

Sanger, or dideoxynucleotide sequencing, is an important tool for biomolecular research. An important trend in DNA sequencing is to find new and innovative ways to provide high-quality, reliable sequences in a more efficient manner, using automated capillary electrophoresis. The Apollo100 combines Sanger cycle sequencing and solid-phase reversible immobilization for product purification in a single instrument with robotic liquid handling and microfluidic (Microscale On-chip Valve) chips that have onboard thermal cycling and pneumatic mixing.

Development of a toxicological gene array and quantitative assessment of this technology.

High-density arrays of DNA bound to solid substrates offer a powerful approach to identifying changes in gene expression in response to toxicants. While DNA arrays have been used to explore qualitative changes in gene regulation, less attention has focused on the quantitative aspects of this technology. Arrays containing expressed sequence tags for xenobiotic metabolizing enzymes, proteins associated with glutathione regulation, DNA repair enzymes, heat shock proteins, and housekeeping genes were used to examine gene expression in response to beta-naphthoflavone (beta-NF).

Gene-targeted B-deficient mice reveal a critical role for B cells in the CD4 T cell response.

The role of B cells in promoting T cell responses is still controversial. In this study, we use JHD mice which have a targeted mutation in the JH gene and are thus rendered deficient in B cells to address this issue. We show here that immunization of JHD mice with soluble antigen fails to prime CD4 T cells, for either clonal expansion or delivery of immunological help for antibody responses.

Light chain editing in kappa-deficient animals: a potential mechanism of B cell tolerance.

The genetic organization of the kappa and lambda light chain loci permits multiple, successive rearrangement attempts at each allele. Multiple rearrangements allow autoreactive B cells to escape clonal deletion by editing their surface receptors. Editing may also facilitate efficient B cell production by salvaging cells with nonproductive light chain (L chain) rearrangements.