The University of California (UC), San Diego division of nephrology/hypertension has implemented a Thermo Scientific NanoDrop 3300 Fluorospectrometer. It will be used for fluorescent detection for mouse glomerular filtration rate (GFR) determination.
The instrument offers a microvolume fluorescent platform for repeated determination of GFR in conscious mice to assess their renal function without surgical procedures. It allows scientists to perform these measurements simply, quickly, and cost effectively, says Thermo Fisher Scientific.
UC San Diego’s division of nephrology/hypertension considers GFR measurement to be the most reliable method in renal function assessment. The technique is utilized by the team to determine GFR under physiological and pathophysiological conditions in mice.
In the past, the division determined GFR by measuring radioactively labeled inulin in blood plasma and urine in anesthetized animals. However, anesthesia has multiple effects on the physiology of the mammalian body, and repetitive measurements are difficult to perform. As this limitation significantly impacted the study designs, the division sought an alternative method.
UC San Diego researchers believe that the Thermo Scientific NanoDrop 3300 fluorospectrometer will enable the measurement of GFR using FITC-inulin. This protocol retains the sensitivity of the traditional assay by using fluorescence detection, while the instrument’s microvolume technology will enable researchers to reduce the volumes of blood required to <10 μL per collection time point.
The NanoDrop 3300 uses a patented cuvetteless sample-retention system for fluorescence measurements using samples as small as 1–2 μL. This enables the division to undertake studies using serial measurements from the same model without compromising the accuracy of the GFR measurement data or the health of the model. In addition, the instrument is capable of analyzing multiple emission profiles from a single sample and has a small footprint.
“The productivity and accuracy of GFR measurements within the division of nephrology has been significantly enhanced,” says Timo Rieg, M.D., assistant professor of medicine at UC San Diego. “By combining the sensitivity of the FITC-inulin technique with the microvolume format of the NanoDrop 3300 instrument, required blood volumes have been reduced. This reduction in blood draw and the possibility to measure GFR under conscious conditions have facilitated further studies in mice that until now were not possible because of the physiological effects of anesthesia and the terminal nature of other methods of GFR determination.”