Establishment of blood analyte intervals for laboratory mice and rats by use of a portable clinical analyzer

Portable clinical analyzers are currently used in human and veterinary medicine for diagnostic testing and blood monitoring; however, normal values for mice and rats of varying genetic backgrounds have not previously been reported. Blood was collected from unanesthetized mice (n = 131) and rats (n = 76) into lithium heparin tubes for analysis using E6+ cartridges for the portable analyzer. Results of glucose, blood urea nitrogen (BUN), sodium, potassium, chloride, hematocrit, and hemoglobin were compared to published ranges provided by a contract diagnostic laboratory. Analyzer ranges were computed as the mean +/- 2 standard deviations of the test samples, such that approximately 95% of tested animals would fall within the resultant range. The degree of overlap between analyzer and published ranges, or the percentage of the published range contained within the analyzer range, was calculated for all analytes. For mice, the ranges of 5 of 7 analytes had more than 57% overlap; for rats, ranges for 6 of 7 analytes had over 65% overlap. After the establishment of normal ranges, the analyzer was used to confirm hyperglycemia in Type I diabetic mice and elevated BUN in rats with induced glomerulosclerosis. The portable analyzer can be a valuable screening tool for both phenotyping and clinical care of rodents, with potential for investigations of both spontaneous and experimental disease in laboratory rodents.