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The ESA Biosciences Inc. Vitamin D HPLC test is for the quantitative determination of 25-hydroxyvitamin D in human serum or EDTA-plasma to be used in the assessment of vitamin D sufficiency. Assay results should be used in conjunction with other clinical or laboratory data to assist the clinician in making individual patient management decisions in an adult population.

The ESA method is a complete kit for measurement of Total 25(OH)D by HPLC with electrochemical (EC) detection. Specific reagents and solid phase extraction columns are included for sample preparation and are employed with user-supplied standard laboratory equipment (centrifuge, test tubes, pipettes, etc.). A 200µL volume of sample (serum or plasma) is mixed with a precipitation reagent, which contains internal standard (IS). The internal standard is a stable vitamin D analogue that is used to correct for variability in extraction recovery and analytical sample volume. After centrifugation, supernatant is poured onto a pre-conditioned SPE column for rapid extraction of 25(OH)D and IS. SPE columns are washed with 2 different reagents and analytes are eluted with a third reagent. The resulting eluent is diluted before analysis. The prepared sample is analyzed with an isocratic HPLC system using an ESA EC detector (Coulochem® III or CoulArray®) equipped with a dual coulometric EC cell. Calibration is accomplished by direct HPLC analysis of authentic standard solutions (i.e. not taken through the extraction step). Analysis requires a specific guard and analytical column, mobile phase and calibration reagents to allow rapid quantitative analysis. A dual EC cell is used with the first, upstream, cell maintained at a specific potential to oxidatively screen possible interfering sample components. The second, downstream cell is maintained at a potential that is optimized for selective 25(OH)D detection. The dual coulometric EC cell is a rugged detector that provides much higher selectivity than commonly used absorbance detectors. This allows the use of lower sample volumes than are typically required with HPLC-UV methods and is less susceptible to interferences. Analytical run time is less than 12 minutes and Total 25(OH)D sample concentration is automatically determined by single-point internal standard quantitation.

For In Vitro Diagnostic Use Only. The LeadCare® II Blood Lead Testing System is an instrumented assay to be used in the quantitation of lead in human whole blood. The Leadcare® II System is suitable for use in a physician's office laboratory environment (POL).

The LeadCare® II Blood Lead Testing System is an instrumented assay utilizing electrochemistry and a unique sensor to be used for the quantitation of lead in whole human blood. Testing can be performed on venous or capillary samples. The system is comprised of an analyzer, sensor (single use, disposable), reagent vial (filled with a measured amount of Treatment Reagent) and a calibration button. The system is powered by 4 AA batteries or AC Adapter. A built in self test checks the electronic functions of the analyzer cach time it is turned on. Blood lead controls are available to monitor the precision and accuracy of the system. The methodology of the system is Anodic Stripping Voltammetry (ASV). Most lead is carried in red blood cells. When a sample of whole blood is mixed with Treatment Reagent, the lead in the red blood cells is released and made available for detection. During the Pb test, the analyzer causes the lead to collect on the sensor. After a specified time, the analyzer removes the lead accumulated on the sensor. The current response (a peak shaped curve) is baseline corrected, quantified and converted to a blood Pb value. The analyzer displays the blood Pb level in units of µg/dL. The test electrode is covered by a thin layer of colloidal gold in an inert polymer matrix. The treatment reagent contains a dilute hydrochloric acid solution in water.