Reagent and reagent kit for analysis of immature leukocyte

1. A reagent for analysis of immature leukocytes comprising:

a polyoxyethylene nonionic surfactant which can damage cell membranes of

erythrocytes and mature leukocytes, having the following formula (I):

R 1 —R 2 —(CH 2 CH 2 O) n —H  (I)

wherein R 1 represents a C 9−25 alkyl, alkenyl or alkynyl group, R 2 represents —O—, —COO— or

and n is an integer of 10 to 40,

a solubilizing agent which can shrink the damaged blood cells and

a dye for staining nucleic acid,

wherein the reagent has an osmotic pressure of not lower than 10 mOsm/kg and lower than 150 mOsm/kg and the pH of the reagent is from greater than 5.0 up to 9.0.

2. The reagent according to claim 1 , wherein the concentration of the surfactant in the reagent is 500 to 15,000 ppm.

3. The reagent according to claim 1 , wherein the polyoxyethylene nonionic surfactant is polyoxyethylene oleyl ether.

4. The reagent according to claim 3 , wherein the polyoxyethylene oleyl ether has the formula (I) wherein n is 15 to 20.

5. The reagent according to claim 1 , wherein the solubilizing agent is selected from the group consisting of a sarcosine derivative, a cholic acid derivative and methylglucanamide.

6. The reagent according to claim 1 , wherein the concentration of the solubilizing agent in the reagent is 100 to 400 ppm when the solubilizing agent is a sarcosine derivative; 50 to 1,300 ppm when the solubilizing agent is a cholic acid derivative; and 500 to 1,100 ppm when the solubilizing agent is methylglucanamide.

7. The reagent according to claim 1 , wherein the dye for staining nucleic acid is at least one dye selected from the group consisting of:

(1) a dye having the following formula (II):

wherein R 1 and R 2 are a lower alkyl group; n is 1 or 2; X − is an anion; and Z is a sulfur atom, an oxygen atom, or a carbon atom which is substituted by a lower alkyl group;

(2) a dye having the following formula (III):

wherein R 1 and R 2 are a lower alkyl group; n is 1 or 2; and X − is an anion:

3) a dye having the following formula (IV):

wherein R 1 is a hydrogen atom or a lower alkyl group; R 2 and R 3 are a hydrogen atom, a lower alkyl group or a lower alkoxy group; R 4 is a hydrogen atom, an acyl group or a lower alkyl group; R 5 is a hydrogen atom or an optionally substituted lower alkyl group; Z is a sulfur atom, an oxygen atom, or a carbon atom which is substituted by a lower alkyl group; n is 1 or 2; and X − is an anion;

(4) a dye having the following formula (V):

wherein X 1 and X 2 are independently Cl or I;

(5) a dye having the following formula (VI):

(6) a dye having the following formula (VII):

(7) a dye having the following formula (VIII):

(8) a dye having the following formula (IX):

(9) a dye having the following formula (X):

(10) propidium iodide or ethidium bromide;

(11) ethidium-acridine heterodimer, ethidium diazide, ethidium homodimer-1, ethidium homodimer-2, ethidium monoazide, trimethylene bis[[3-[[4-[[(3-methylbenzothiazol-3-ium)-2-yl]methylene]-1,4-dihydroquinoline]-1-yl]propyl]dimethylaminium]tetraiodide (TOTO-1), 4-[(3-methylbenzothiazol-2(3H)-ylidene)methyl]-1-[3-(trimethylaminio)propyl]quinolinium diiodide (TO-PRO-1), N,N,N′,N′-tetramethyl-N,N′-bis[3-[4-[3-[(3-methylbenzothiazol-3-ium)-2-yl]-2-propenylidene]-1,4-dihydroquinoline-1-yl]propyl]1,3-propanediaminium tetraiodide (TOTO-3), or 2-[3-[[1-[3-(trimethyaminio)propyl]-1,4-dihydroquinoline]-4-ylidene]-1-propenyl]3-methylbenzothiazol-3-ium diiodide (TO-PRO-3).

8. A reagent kit for analysis of immature leukocytes comprising:

a first reagent which comprises a polyoxyethylene nonionic surfactant that can damage cell membranes of erythrocytes and mature leukocytes, having the following formula (I):

R 1 —R 2 —(CH 2 CH 2 O) n —H  (I)

wherein R 1 represents a C 9−25 alkyl, alkenyl or alkynyl group, R 2 represents —O—, —COO— or

and n is an integer of 10 to 40,

a solubilizing agent that can shrink the damaged blood cells wherein the first reagent has an osmotic pressure of not lower than 10 mOsm/kg and lower than 150 mOsm/kg and the pH of the first reagent is from greater than 5.0 up to 9.0, and

a second reagent which comprises a dye for staining nucleic acid.

9. A method for classifying leukocytes comprising the steps of:

mixing a biological sample possibly containing immature leukocytes with a reagent for analysis of immature leukocytes comprising a surfactant which can damage cell membranes of erythrocytes and mature leukocytes, having the following formula (I):

R 1 —R 2 —(CH 2 CH 2 O) n —H  (I)

wherein R 1 represents a C 9−25 alkyl, alkenyl or alkynyl group, R 2 represents —O—, —COO— or

and n is an integer of 10 to 40,

a solubilizing agent which can shrink the damaged blood cells and a dye for staining nucleic acid, wherein the reagent has an osmotic pressure of not lower than 10 mOsm/kg and lower than 150 mOsm/kg and the pH of the reagent is from greater than 5.0 up to 9.0, to stain nucleic acid of mature leukocytes, and

measuring at least one scattered light and at least one fluorescence of the immature leukocytes treated in the previous step to classify immature leukocytes based on differences of intensities of the scattered light and the fluorescence.