Abstract: Methods and systems are provided for determining a characteristic of an in vivo sensor. A transmit field, operative to induce a response signal in an associated in vivo sensor, is generated at a transmitting component having an associated orientation. The response signal is received at a receiving component, having an associated orientation. The coupling between the transmitting component and the receiving component is measured. The associated orientation of at least one of the transmitting component and the receiving component is rotated as to reduce the measured coupling.

Abstract: The present invention provides a novel reporter gene assay. In particular, the present invention provides a histochemical reporter gene assay employing ?-L-arabinofuranosidase in combination with a chromogenic ?-L-arabinofuranosidase substrate. The ?-L-arabinofuranosidase histochemical reporter assay may be utilized to characterize gene regulatory regions of interest either alone or in combination with other assays.

Abstract: The invention provides a Dre/rox recombinase system. In particular, the invention provides Dre polypeptides that can catalyze site-specific recombination at rox sites but not at lox sites. The Dre/rox system can be utilized in a number of genetic manipulations either alone or in combination with other recombinase systems.

Abstract: The invention provides a novel Cre/lox system with lox sites having an extended spacer region. In particular, the invention provides Cre mutant polypeptides that can catalyze site-specific recombination at lox sites typically having from one to three additional base pairs in the spacer region. The Cre/lox system can be utilized in a number of genetic manipulations either alone or in combination with other recombinase systems.