System and method for distinguishing blood components

1. A method for measuring concentrations of blood cell components, the method comprising:

obtaining a blood sample from a subject, the blood sample comprising red blood cells (RBCs), white blood cells (WBCs), and platelets (PLTs);

mixing the blood sample with a non-lysing aqueous solution to form a sample mixture comprising a predetermined tonicity;

passing the sample mixture through a flow cell;

emitting light towards the flow cell;

measuring an amount of light absorbed by the RBCs and obtaining, from the amount of light absorbed by the RBCs, a value consisting essentially of an RBC absorption value, an amount of light scattered by WBCs to obtain a WBC scatter value, and an amount of light scattered by PLTs to obtain a PLT scatter value; and

determining a concentration of the RBCs, WBCs, and PLTs present in the sample mixture based on the RBC absorption value, the WBC scatter value, and the PLT scatter value, respectively,

wherein the sample mixture does not comprise a dye.

2. The method according to claim 1 , wherein the sample mixture consists of the blood sample and saline.

3. The method according to claim 2 , wherein the saline is buffered saline.

4. The method according to claim 2 , wherein the predetermined tonicity of the sample mixture is 260-330 milliosmolar (mOsm).

5. The method according to claim 1 , wherein light absorbed by the RBCs in the sample mixture in the flow cell is detected by a single absorption detector.

6. A method for measuring concentrations of blood cell components, the method comprising:

obtaining a blood sample from a subject, the blood sample comprising red blood cells (RBCs), white blood cells (WBCs), and platelets (PLTs);

mixing the blood sample with a non-lysing aqueous solution to form a sample mixture comprising a predetermined tonicity;

passing the sample mixture through a flow cell;

emitting light towards the flow cell;

measuring an amount of light absorbed by the RBCs;

obtaining, from the amount of light absorbed by the RBCs, a value consisting essentially of an RBC absorption value;

measuring an amount of light scattered by WBCs and PLTs to obtain a WBC scatter value and a PLT scatter value; and

determining a concentration of each of the RBCs, WBCs, and PLTs present in the sample mixture based on the RBC absorption value, the WBC scatter value, and the PLT scatter value,

wherein the amount of light absorbed by the RBCs is detected by an absorption detector within a first cone of a first predetermined number of degrees around the incident light,

wherein the first predetermined number of degrees is from about 0 to about 26 degrees.

7. The method according to claim 6 , further comprising:

measuring an amount light side-scattered by the RBCs, WBCs, and PLTs outside the first cone and within a second cone of a second predetermined number of degrees around the incident light.

8. The method according to claim 7 , wherein the second predetermined number of degrees around the incident light is from about 75 degrees to about 105 degrees.

9. The method according to claim 6 , wherein substantially all of the light scattered by the WBCs and PLTs is captured within the first cone.

10. The method according to claim 6 , wherein the light comprises a wavelength in the range of about 400 nm to about 450 nm.

11. The method according to claim 6 , wherein the sample mixture does not comprise a dye.

12. A method for measuring concentrations of blood cell components, the method comprising:

obtaining a blood sample from a subject, the blood sample comprising red blood cells (RBCs), white blood cells (WBCs), and platelets (PLTs);

mixing the blood sample with a non-lysing aqueous solution to form a sample mixture comprising a predetermined tonicity;

passing the sample mixture through a flow cell;

emitting light towards the flow cell;

measuring an amount of light absorbed by the RBCs;

obtaining, from the amount of light absorbed by the RBCs, a value consisting essentially of an RBC absorption value;

measuring an amount of light scattered by WBCs and PLTs to obtain a WBC scatter value and a PLT scatter value; and

determining a concentration of each of the RBCs, WBCs, and PLTs present in the sample mixture based on the RBC absorption value, the WBC scatter value, and the PLT scatter value,

wherein the amount of light absorbed by the RBCs and amount of light scattered by WBCs and PLTs are measured in a single measurement cycle.

13. The method according to claim 12 , wherein the single measurement cycle comprises measurement of only light absorption and light scatter.

14. The method according to claim 12 , wherein the sample mixture does not comprise a dye.