Systems and methods of fluidic sample processing
The present invention provides fluidic devices and systems that allow detection of analytes from a biological fluid. The methods and devices are particularly useful for providing point-of-care testing for a variety of medical applications.
1. A method of calculating an apparent dilution ratio utilized in diluting a blood sample for running a blood test, comprising:
a) providing a plasma sample derived from a diluted blood sample;
b) measuring conductivity of the plasma sample; and
c) comparing the measured conductivity to a set of predetermined values showing relationship of conductivity values and dilution ratios that are employed to dilute a blood sample, thereby calculating the apparent dilution ratio utilized in diluting the blood sample.
2. The method of claim 1 , wherein the blood sample is diluted prior to running the blood test.
3. The method of claim 1 , wherein the plasma sample derived from a diluted blood sample is substantially free of red blood cells.
4. The method of claim 1 , wherein conductivity of the plasma sample is inversely proportional to the apparent dilution ratio.
5. The method of claim 1 , wherein the measuring of the conductivity of the plasma sample is performed using at least two electrodes spaced at different locations.
6. The method of claim 5 , wherein the electrodes are formed of stainless steel.
7. The method of claim 5 , wherein the electrodes are spaced apart by 5 mm to 20 mm.
8. The method of claim 1 , wherein an AC voltage is applied to the plasma sample.
9. The method of claim 8 , wherein a relationship between a current induced by the AC voltage applied and the conductivity of the plasma sample is determined.
10. The method of claim 9 , wherein the measured conductivity is amplified, reshaped, buffered, and/or sent to a microprocessor that outputs a DC voltage correlated to the measured conductivity.
11. The method of claim 1 , wherein the blood sample has a volume from about 1 uL to about 500 uL.
12. The method of claim 1 , wherein the predetermined values form a substantially linear calibration curve.
13. The method of claim 1 , wherein the temperature of the plasma sample is fixed.
14. The method of claim 1 , wherein the conductivity is measured with a calibration unit contained in a device that also collects the blood sample.