The SpinVessel system provides a methodology using pulsed radial flow to gently mix and uniformly suspend particulates (cells, magnetic beads, silica beads, and microcarrier beads) for automated assays. SpinVessels are well suited for aliquoting on robotic liquid handlers and with robotic reagent dispensers, as well as manually. The SpinVessel system combines two critical features: (1) special internal side fins and projections in the bottom of the vessels and (2) an instrument that quickly spins the vessels and repeatedly reverses the spin direction. This rapid reversing motion sends multiple pulses of fluid up the side walls of the SpinVessel, creating a circular radial flow pattern. We tested five different particulates and six different SpinVessels with volume capacities varying from 50 mL to 1200 mL. SpinVessels are compatible with either single-, 8-, 12-, 96-, or 384-channel pipettors or with siphon tubing on robotic reagent dispensers. Experiments have demonstrated high viability of cells and undamaged morphology of microcarrier beads even after hours of constant agitation. The uniformity of aliquots collected at various vertical depths and horizontally across the SpinVessels demonstrated that cells, magnetic beads, and silica beads were uniformly suspended throughout the height and breadth of the SpinVessels, and uniformity of samples was consistent from the beginning to the end of the aliquoting procedure. Only 5 min of mixing is required to resuspend settled particulates. This novel mixing methodology has many applications in laboratory automation where particulate aliquot uniformity and/or particulate integrity are important to automating assays.

Neuromedin-U (NMU) mediates several physiological functions via its two cognate receptors, NMUR1 and NMUR2. Disentangling the individual roles of each receptor has largely been undertaken through the use of transgenic mice bearing a deletion in one of the two receptors or by testing native molecules (NMU or its truncated version NMU-8) in a tissuespecific manner, in effect, taking advantage of the distinct receptor expression profiles. These strategies have proved quite useful despite the inherent limitations of overlapping receptor roles and potential compensatory influences of germline gene deletion. With these considerations in mind, the availability of potent, selective NMU compounds with appropriate pharmacokinetic profiles would advance the capabilities of investigators undertaking such efforts. Here, we evaluate a recently reported NMUR2-selective peptide (compound 17) for its in vitro potency (mouse and human), binding affinity, murine pharmacokinetic properties, and in vivo effects. Despite being designed as an NMUR2 agonist, our results show compound 17 unexpectedly binds but does not have functional activity on NMUR1, thereby acting as an R1 antagonist while simultaneously being a potent NMUR2 agonist. Furthermore, evaluation of compound 17 across all known and orphan G-protein-coupled receptors demonstrates multiple receptor partners beyond NMUR2/R1 binding. These properties need to be appreciated for accurate interpretation of results generated using this molecule and may limit the broader ability of this particular entity in disentangling the physiological role of NMU receptor biology.