[35]

MURINE AUTOMATED URINE SAMPLER: USE OF CHLORHEXIDINE/N-PROPYL GALLATE FOR HANDS-OFF SMALL ANIMAL URINE PRESERVATION.   V.H. Quinlivan1, K.H. Aull1, J.M.Weiss2, E. Guerra3, E.B. Wagner4. 1MIT Department of Biology, 2SUNY Binghamton, 3 Payload Systems, Inc., Cambridge, MA, 4Harvard-MIT Division of Health Sciences and Technology.

   In both crewed and uncrewed space research platforms, as well as in largely automated ground-based studies, such as centrifugation, the provision of urine sampling and analysis would offer unique insight into processes of metabolic and musculoskeletal adaptation.  This process, however, typically requires careful collection in liquid form, preservation through freezing, and analysis of samples within a few days of room temperature storage. Developed in conjunction with the Mars Gravity Biosatellite Program, the Murine Automated Urine Sampler (MAUS) is the first system to provide small-mammal urine collection in a low-mass, low-power autonomous configuration with long-term storage capability. MAUS extends current capabilities for in situ chemical urine sampling, utilizing a unique hydrophilic polyvinylidine fluoride membrane imbued with NASA's preservative chlorhexidine / n-propylgallate (CPG)(Smith, 1996) to collect small mammal liquid waste and preserve urine markers that are key to gravitational physiology.  The work presented demonstrates up to six weeks of time-stamped sample collection and analyte preservation, focusing on basic moieties that demonstrate renal function and musculoskeletal integrity.  In ground studies simulating Mars Gravity's biosatellite mission, the MAUS hardware has demonstrated the capability to filter out contaminating food particles and feces and to collect weekly urine samples. We verify that the dried samples can be extracted from the system, reconstituted, and tested for analytes important to the study of bone and muscle loss, such as calcium, sodium, potassium, and urea. Extension of this capability to more complex analytes, including 3-methylhistidine, corticosterone, and n-telopeptides, will be discussed. This study also presents the results of our experiments with the preservation capabilities of CPG for dehydrated samples.This research was supported by NASA SBIR Grant #NNA04CB83C.