A prototype mass spectrometer for in situ analysis of cave atmospheres.

Research in cave environments has many applications: studying local hydrogeologic activity, paleoclimate studies, analyzing white nose syndrome in bat populations, analogs for underground atmospheres in mining facilities, carbon sequestration efforts, and terrestrial analogs for planetary caves. The atmospheres of many caves contain tracers of current geological and biological activity, but up to this point, in situ studies have been limited to sensors that monitor individual components of the cave atmosphere. A prototype cave mass spectrometer system was assembled from commercial off-the-shelf parts to conduct surveys of atmospheric compositions inside four local Texas caves and to perform atmospheric analysis of two aquifer wellheads to a depth of 60 m.

An improved Abbott ARCHITECT assay for the detection of hepatitis B virus surface antigen (HBsAg).

Background: The sensitive and accurate detection of hepatitis B virus surface antigen (HBsAg) is critical to the identification of infection and the prevention of transfusion transmitted disease. Improvement in HBsAg assay sensitivity is essential to reduce the window to detect an acute HBV infection. Additionally, the sensitive detection of HBsAg mutants that continue to evolve due to vaccine escape, immune selection and an error prone reverse transcriptase is a necessity.

Mass spectrometric and physiological validation of a sensitive, automated, direct immunoassay for serum estradiol using the Architect.

Background: Measurement of estradiol (E(2)) plays a critical role in the diagnosis and clinical management of reproductive disorders. The challenge for all currently available direct methods for measuring E(2) is to provide accuracy and precision across a wide dynamic range.

Methods: We describe the development and multi-site performance evaluation of a direct E(2) assay on the Architect i2000.