JPH11166932A - Stabilization method for human hemoglobin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new stabilization method for human hemoglobin, to provide a buffer solution by which a sample containing hemoglobin is dissolved so as to be held stably, to provide a high-accuracy measuring method for human hemoglobin and to provide a measuring method in which bleeding from a basilar digestive canal is detected at an early stage. SOLUTION: In a method in which human hemoglobin is stabilized in a solution, the human hemoglobin and one kind or two or more kinds of substances selected from a group composed of casein, boric acid or its salt, an aluminum salt, thiourea, calcium chloride and calcium acetate are made to coexist in the solution. When the method to stabilize the human hemoglobin is applied in order to detect the human hemoglobin, it is possible to restrain the human hemoglobin from being denatured and decomposed in various solutions such as, e.g. a standard solution, a positive control solution and a sample to be inspected (e.g. a dejection dissolved solution). Thereby, the concentration of the human hemoglobin can be measured more precisely.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for stabilizing human hemoglobin in a solution, a buffer for dissolving a substance containing human hemoglobin, a buffer for stably retaining human hemoglobin, or a stable solution containing human hemoglobin. It is about a solution. Furthermore, the present invention relates to a stool collection container for measuring human hemoglobin, which contains a buffer for stably retaining human hemoglobin.

[0002] By applying the method for stabilizing human hemoglobin of the present invention to the detection of human hemoglobin, various methods such as a standard solution and a positive control solution (hereinafter, referred to as a positive control solution) can be used.
A positive control solution) and a test sample (for example,
The denaturation and / or degradation of human hemoglobin in the stool solution) is suppressed, and the concentration of human hemoglobin can be measured more accurately.

[0003]

2. Description of the Related Art In recent years, detection of fecal occult blood components, particularly human hemoglobin, in feces due to bleeding from the digestive tract has been widely performed as a method for early detection of lower digestive organ diseases such as colorectal cancer. As a method for detecting such human hemoglobin, an immunological detection method that does not require restrictions on food intake or drug administration, which is conventionally required, has become widespread, and has been established as a simple test method.

As the immunological detection method of human hemoglobin, for example, a one-dimensional immunodiffusion method utilizing a precipitation line between an anti-human hemoglobin antibody and a human hemoglobin in a test sample on an agar plate, an anti-human hemoglobin antibody, Reverse passive hemagglutination using sensitized animal blood cells, latex agglutination using latex particles sensitized with anti-human hemoglobin antibody, enzyme immunization or radioimmunization using anti-human hemoglobin antibody labeled with enzymes or radioactive elements, Colloidal gold agglutination colorimetric method using colloidal gold particles sensitized with an anti-human hemoglobin antibody.

[0005] In the above detection method, human hemoglobin, which is a test substance, is usually subjected to a test in a solution state.
For example, in a fecal occult blood test, feces are dissolved in a physiological saline solution or a buffer solution, and the solution is used as a test sample for measuring human hemoglobin.

[0006] It is known that human hemoglobin in a test sample is denatured or decomposed with increasing temperature and time. The denaturation or degradation of human hemoglobin inactivates the antigenic determinant, and the detection sensitivity in the immunological detection method is significantly reduced. In particular, when the concentration of human hemoglobin is low, the concentration of human hemoglobin falls below the detection limit due to the above-mentioned denaturation or decomposition, resulting in erroneous diagnosis. Similar denaturation or degradation of human hemoglobin occurs in a positive control solution used for confirming the test performance or in a hemoglobin standard solution used for quantifying hemoglobin, which is an obstacle to accurate measurement.

[0007] By the way, the actual situation of the fecal occult blood test is that the subject himself collects the stool at home or the like, dissolves it in the stool solution, and mails or brings the subject to the hospital in many cases. For this reason, the sample of the fecal occult blood test is often kept in a solution state for several days from the time of collecting the stool to the time of starting the test at a laboratory. In addition, even when a stool is collected by a laboratory, a large amount of time may be required for a test for fecal occult blood since another test is performed. The test under such circumstances is not preferable in that the denaturation or degradation of human hemoglobin occurs as described above, and accurate measurement cannot be performed.

For the purpose of preventing such denaturation or decomposition of human hemoglobin, a method of adding various substances to a stool lysate for detecting fecal occult blood has been studied. For example, addition of bovine serum albumin (BSA) or general antibacterial agents such as thimerosal and sodium azide, addition of animal serum (Japanese Patent Application Laid-Open No. 4-145366), and addition of saccharides (Japanese Patent Application Laid-Open No. 63-2)
No. 43756), addition of sodium azide, albumin and lactic acid (JP-A-6-281654), addition of lytic enzyme (JP-A-5-69466), addition of protease inhibitor (JP-A-3-279859) Gazette) and addition of iron protoporphyrin (Japanese Patent Application Laid-Open No. H5-281227). Also, a method of controlling pH (Japanese Patent Application Laid-Open No. 5-281226) has been reported. Further, as a method for preventing the decomposition of hemoglobin, a method for preventing the decomposition of hemoglobin by adding a specific nitrogen-containing compound to hemoglobin to prevent the release of iron from the heme portion (Japanese Patent Laid-Open No. 60-35270) or a method for preventing hemoglobin A method for suppressing the degradation of hemoglobin by coexisting a non-penicillin antibiotic in a sample containing the substance (JP-A-7-72154) has been reported. In addition, a method of adding a chelating reagent (JP-A-5-99923 and JP-A-2-21859) and a method of adding a water-soluble transition metal complex (JP-A-7-229902) have been reported. . Further, addition of sodium fluoride (Japanese Patent Application Laid-Open No. Hei 7-91026), addition of animal hemoglobin (Japanese Patent Application Laid-Open No. Hei 2-296149), and a method of coexisting iron proteins other than hemoglobin and ferricyan ion with hemoglobin (particularly). Kaihei 8-2620
No. 20) has been reported.

However, these known techniques for stabilizing human hemoglobin have not yet sufficiently suppressed the denaturation or degradation of human hemoglobin in a test sample containing feces.

Further, in order to use as a positive control solution or a standard solution containing no stool, even if the above-mentioned known technique is used for stabilizing human hemoglobin prepared from human hemoglobin or red blood cells in the solution, Hemoglobin is unstable and has not sufficiently prevented its denaturation or decomposition. Therefore, there is a demand for a method for stably retaining various hemoglobins in a solution, such as hemoglobin in feces, a hemoglobin preparation, and hemoglobin prepared from red blood cells.

[0011]

Thus, an object of the present invention is to provide a novel method for stabilizing human hemoglobin. More specifically, it is an object of the present invention to obtain more accurate measurements by increasing the stability of human hemoglobin in a test sample containing feces. Another object of the present invention is to provide a stool solution for stabilizing human hemoglobin contained therein when stool is dissolved and used as a test sample, and a stool collection container containing the solution. It is in. It is a further object of the present invention to provide an excellent positive control solution or hemoglobin standard solution in which human hemoglobin is stabilized.

In view of the above circumstances and objects, the present inventors have conducted intensive studies to find an improved stabilization method for suppressing denaturation or decomposition of human hemoglobin in a solution. , Casein, boric acid or a salt thereof, an aluminum salt, thiourea, calcium chloride, and a method for stabilizing hemoglobin by coexisting at least one substance selected from the group consisting of calcium acetate in a solution Thus, the present invention has been completed.

[0013]

SUMMARY OF THE INVENTION The present invention is a method for stabilizing human hemoglobin in a solution, comprising the steps of: providing human hemoglobin with casein, boric acid or a salt thereof, aluminum salt, thiourea, calcium chloride, and calcium acetate; And at least one substance selected from the group consisting of:

[0014] In a preferred embodiment, the two or more substances are casein and at least one substance selected from the group consisting of boric acid or a salt thereof, an aluminum salt, thiourea, calcium chloride and calcium acetate. including.

[0015] In a preferred embodiment, the aforementioned 2
The at least one substance includes boric acid or a salt thereof, and at least one substance selected from an aluminum salt, thiourea, calcium chloride, and calcium acetate. In a preferred embodiment, the solution has a pH in the range of 5.5 to 7.5. In a preferred embodiment, the human hemoglobin is faecal human hemoglobin.

The present invention also relates to one or more of casein, boric acid or a salt thereof, an aluminum salt, thiourea, calcium chloride and calcium acetate.
The present invention relates to a buffer for dissolving a substance containing human hemoglobin, which contains one or more substances.

In a preferred embodiment, the two or more substances are casein and at least one substance selected from boric acid or a salt thereof, an aluminum salt, thiourea, calcium chloride and calcium acetate.

In a preferred embodiment, the above-mentioned 2
The at least one substance is boric acid or a salt thereof and at least one substance selected from aluminum salts, thiourea, calcium chloride, and calcium acetate. In a preferred embodiment, the pH of the buffer is from 5.5 to 7.5.
Range. In a preferred embodiment, the human hemoglobin-containing substance is human feces.

Further, the present invention comprises human hemoglobin and one or more substances selected from the group consisting of casein, boric acid or a salt thereof, an aluminum salt, thiourea, calcium chloride and calcium acetate. It relates to a solution containing human hemoglobin.

In a preferred embodiment, the two or more substances are casein and at least one substance selected from boric acid or a salt thereof, an aluminum salt, thiourea, calcium chloride and calcium acetate.

In a preferred embodiment, the two or more substances are boric acid or a salt thereof, an aluminum salt,
It is at least one substance selected from thiourea, calcium chloride and calcium acetate. In a further preferred embodiment, the buffer has a pH in the range of 5.5 to 7.5. In a preferred embodiment, the human hemoglobin-containing solution is a human hemoglobin positive control solution or a human hemoglobin standard solution.

Furthermore, the present invention provides a human hemoglobin-containing substance containing one or more substances selected from the group consisting of casein, boric acid or a salt thereof, an aluminum salt, thiourea, calcium chloride and calcium acetate. The present invention relates to a stool container for measuring human hemoglobin, comprising a lysis buffer.

In a preferred embodiment, the two or more substances are casein and at least one substance selected from boric acid or a salt thereof, an aluminum salt, thiourea, calcium chloride and calcium acetate.

In a preferred embodiment, the above-mentioned 2
The at least one substance is boric acid or a salt thereof and at least one substance selected from aluminum salts, thiourea, calcium chloride, and calcium acetate. In a further preferred embodiment, the pH of the buffer is from 5.5 to 7.5.
Range.

According to the present invention, human hemoglobin can be stabilized in a solution. Further, according to the present invention, a stable positive control solution and hemoglobin standard solution that can be used for a long time can be provided. Also,
It is possible to provide a stool dissolution buffer for dissolving stool and stabilizing human hemoglobin therein and a stool collection container containing the buffer, and further in the field of clinical examination,
A method for improving the accuracy of hemoglobin measurement can be provided. Therefore, the above objects can be achieved by the present invention.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION The human hemoglobin used in the method of the present invention may be any of human hemoglobin contained in feces, human hemoglobin prepared from erythrocytes, and commercially available human hemoglobin. Human hemoglobin from erythrocytes is prepared by collecting human erythrocytes by a conventional method, or by purchasing commercially available human erythrocytes and destroying the erythrocytes in distilled water.

As casein, boric acid or a salt thereof, aluminum salt, thiourea, calcium chloride and calcium acetate used for stabilizing human hemoglobin in a solution, commercially available products can be used.

The concentration of casein used in the present invention is about 0.01
% To about 1.0% (% by weight, the same applies hereinafter), preferably about 0.05% to about 0.2%.

Examples of the borate include sodium borate, potassium borate and the like. The concentration of boric acid or a salt thereof is about 0.02% to about 2.0% as boric acid, and preferably about 0.1% to about 0.5%.

Examples of the aluminum salt include aluminum chloride, ammonium aluminum sulfate, potassium aluminum sulfate and the like. The concentration of the aluminum salt is about 0.001% to about 0.5%, preferably about 0.005% to about 0.1%, as the concentration of aluminum chloride.

The concentration of thiourea is from about 0.00005% to about 0.01%
And preferably about 0.0001% to about 0.001%.
The concentration of calcium chloride and calcium acetate is about 0.005
% To about 2.0%, preferably about 0.02% to about 0.4%.

[0032] Casein, boric acid or a salt thereof,
The aluminum salt, thiourea, calcium chloride and calcium acetate may be added alone, or two or more of these substances may be added in combination.

When two kinds of substances are used in combination, casein, boric acid or a salt thereof, an aluminum salt,
It is preferable to include at least one substance selected from the group consisting of thiourea, calcium chloride, and calcium acetate. Preferred combinations include casein and boric acid, casein and aluminum chloride, casein and thiourea, or casein and calcium chloride.

It is also preferable to include boric acid or a salt thereof and at least one substance selected from aluminum salts, thiourea, calcium chloride and calcium acetate. Preferred combinations include boric acid and aluminum chloride, boric acid and thiourea, and boric acid and calcium chloride.

Further, aluminum chloride and thiourea, aluminum chloride and calcium chloride, aluminum chloride and calcium acetate may be used in combination, or thiourea and calcium chloride may be used in combination.

In the case of three types of combinations, casein, boric acid and aluminum chloride, casein and boric acid and thiourea, casein and boric acid and calcium chloride, casein and boric acid and calcium acetate, boric acid and aluminum chloride And calcium chloride, and combinations of boric acid, thiourea and calcium chloride are preferred. Further, four or more kinds of substances may be included. When two or more of these substances coexist, the addition concentration may be within the above concentration range.

When one or more of the above substances are contained, the pH of the solution for stabilizing human hemoglobin is about pH
It ranges from 5.0 to about 8.5, preferably from about 5.5 to about 7.5, more preferably from about 6.0 to about 7.0. This is because the stability of hemoglobin may be impaired under extreme acid or alkaline conditions. Appropriate buffers are used to maintain the pH.

A buffer for dissolving the substance containing human hemoglobin of the present invention (hereinafter simply referred to as the buffer of the present invention)
Contains one or more substances selected from the group consisting of casein, boric acid or a salt thereof, an aluminum salt, thiourea, calcium chloride, and calcium acetate. Thus, when the substance containing human hemoglobin is dissolved in the buffer of the present invention, human hemoglobin is stably retained. The pH of the buffer of the present invention is about
It ranges from 5.0 to about 8.5, preferably from about 5.5 to about 7.5, more preferably from about 6.0 to about 7.0. There is no particular limitation as long as the buffer maintains the pH. Suitable buffers include phosphate buffers, citrate buffers, β
-Β 'dimethylglutarate buffer, Good's buffer and the like. Good's buffers include glycine, glycylglycine, tris-hydrochloric acid, MES (2- (N-monophorino) ethanesulfonic acid), HEPES (N-2-hydroxyethyl-piperazine-N'-ethanesulfonic acid), T
ES (N-tris (hydroxymethyl) methyl-2-aminoethanesulfonic acid), MOPS (3- (N-morpholino) propanesulfonic acid) and the like are preferably used.

The human hemoglobin-containing solution of the present invention comprises one or more substances selected from the group consisting of human hemoglobin and the above casein, boric acid or a salt thereof, an aluminum salt, thiourea, calcium chloride and calcium acetate. It contains. Thereby, human hemoglobin is stably maintained in the solution containing human hemoglobin of the present invention. The human hemoglobin-containing solution of the present invention is specifically a positive control solution or a human hemoglobin standard solution. The concentration of human hemoglobin in the solution containing human hemoglobin is suitably from about 10 ng / ml to about 1 mg / ml.

The method for stabilizing human hemoglobin of the present invention,
In a solution containing human hemoglobin or a buffer for dissolving a substance containing human hemoglobin, antibacterial agents (eg, sodium azide), protein stabilizers (eg, albumin), sodium chloride, etc. Is desirably added. The concentration of sodium azide is about 0.02 to about 2.0%, preferably about 0.1 to about 0.5%. The albumin is preferably bovine serum albumin (BSA), and the concentration is preferably about 0.01 to about 2.0%, preferably about 0.05 to about 0.5%. Sodium chloride is preferably near the concentration of physiological saline. Further, other inorganic salts, saccharides, amino acids, chelating agents and the like may be added.

The stool collection container for measuring human hemoglobin of the present invention contains the buffer of the present invention. The buffer is preferably
Glass and plastic containers contain the appropriate amount. The stool collection container includes a stool collection device (for example, a stick)
Can be attached, and the feces are collected with the feces collection device,
A fixed amount of feces can be dissolved in the buffer.

The method for measuring human hemoglobin in the present invention is an immunological method. That is, an antigen-antibody reaction between a human hemoglobin sample dissolved in the buffer of the present invention, human hemoglobin prepared from red blood cells, or human hemoglobin in human feces and an anti-human hemoglobin antibody is performed.
Antigen-antibody reaction conditions are well known to those skilled in the art. The reaction is carried out at an appropriate buffer and temperature, for example, 30 ° C to 40 ° C for an appropriate time.

Further, for the purpose of controlling the antigen-antibody reaction, polyethylene glycol (2,000, 4,000, 6,
000, 20,000) or dextran may be added to the human hemoglobin-containing solution or the buffer for dissolving the human hemoglobin-containing substance of the present invention. The concentration to be added is preferably about 0.001 to about 4%.

As a method for measuring human hemoglobin, any method may be used as long as it is an immunological detection method using an anti-human hemoglobin antibody. Preferably, a gold colloid aggregation colorimetric method is used. In this method, human hemoglobin is detected by optically measuring the color difference (color tone change) generated when the colloidal gold-labeled anti-human hemoglobin antibody aggregates via hemoglobin. As the colloidal gold-labeled anti-human hemoglobin antibody, an anti-hemoglobin antibody may be prepared by a well-known method and labeled with gold colloid, or a commercially available lyophilized gold colloid reagent (for example, Maycheek hemoplate (auto): Japan Shoji Co., Ltd.)
It may be dissolved in an appropriate buffer and used as a gold colloid reagent solution.

[0045]

EXAMPLES Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples. (Example 1) (1) Preparation of human hemoglobin After commercially available human erythrocytes were destroyed in distilled water, the cyanmethemoglobin method (Nescort hemokit-N; Nihon Shoji)
Hemoglobin concentration was measured. afterwards,
A human hemoglobin solution (1 mg / ml) was prepared using physiological saline and stored frozen at -40 ° C.

(2) Preparation of control solution 1 mg / ml human feces was dissolved in 30 mM MES buffer pH 6.3 containing 0.9% sodium chloride, 1.8% polyethylene glycol 20,000, 0.2% BSA and 0.2% sodium azide, A control solution was prepared.

(3) Preparation of test solution The substances shown in Table 1 were added to the control solution obtained in (2),
Test solutions were prepared. In addition, the concentration of the additive substance shown in Table 1
(%) Indicates the final concentration (% by weight) of the substance in the test solution. The same applies to Tables 2 and 3.

(4) Sample diluent 0.9% sodium chloride, 1.8% polyethylene glycol
20,000, 0.05% BSA, 0.1% DL-asparagine, 0.05%
30 mM MES buffer pH 5.7 containing sodium azide
Was prepared and used as a sample diluent.

(5) Test Method The human hemoglobin prepared in the above (1) was added to the above-mentioned control solution and test solution to a concentration of 200 ng / ml to prepare a sample, and human hemoglobin was measured by the following method. For the measurement of human hemoglobin, a freeze-dried commercially available colloidal gold reagent (Maycheck Hemoplate (Auto): manufactured by Nippon Shoji Co., Ltd.) was prepared using 0.1% BSA, 3.0% mannitol, and 0.1% BSA.
10 mM HEPES buffer containing 05% sodium azide
The solution was dissolved in 30 ml of H7.5 and used as a gold colloid reagent solution. A 25 μl sample was dispensed into a microplate for EIA, and 50 μl of a sample diluent and 100 μl of a gold colloid reagent solution were added, followed by stirring with a micromixer (manufactured by Sanko Pure Chemical Industries, Ltd.) for 10 seconds. Absorbance 1 minute and 7 minutes after addition of gold colloid reagent (main wavelength 540nm, sub wavelength
700 nm) using a microplate reader (manufactured by Wako Pure Chemical Industries, Ltd.), and the difference in absorbance was determined.

Measurements were taken on the day of sample preparation and after storage at 37 ° C. for one day. The difference between the absorbance on the day of preparation of each sample and 37 ° C, 1
The residual ratio (%) was determined from the ratio of the absorbance difference after storage for one day, and used as an index for hemoglobin stabilization. Table 1 shows the results.

[0051]

[Table 1]

As shown in Table 1, the residual ratio of the solution containing casein, aluminum chloride, ammonium aluminum sulfate, potassium aluminum sulfate, boric acid, thiourea, calcium chloride, and calcium acetate was lower than that of the control solution. High, the effect of stabilizing hemoglobin was observed.

(Example 2) Among the substances which showed a hemoglobin stabilizing effect in Example 1, casein, aluminum chloride, boric acid, calcium chloride and thiourea were confirmed for stabilizing effect and added. The concentration was studied. Confirmation of the stabilizing effect was performed in the same manner as in Example 1.
Table 2 shows the results.

[0054]

[Table 2]

Casein, aluminum chloride, boric acid, calcium chloride, and thiourea each had a stabilizing effect at the concentrations studied.

(Example 3) The stabilizing effect of a combination of the substances having a hemoglobin stabilizing effect in Examples 1 and 2 was evaluated in the same manner as in Example 1. Table 3 shows the results.

[0057]

[Table 3]

Casein, aluminum chloride, thiourea,
As in the case where calcium chloride and boric acid were independently blended, a stabilizing effect was observed when these substances were combined and present.

[0059]

According to the method for stabilizing human hemoglobin in a solution of the present invention, casein, boric acid or a salt thereof,
By containing one or more substances selected from aluminum salts, thiourea, calcium chloride and calcium acetate, denaturation or degradation of human hemoglobin can be suppressed. According to the present invention, it becomes possible to stabilize human hemoglobin in a test sample containing feces for several days in a fecal occult blood test, and it can be stored in a stable state until it is detected in a laboratory, and a more accurate measurement result can be obtained. Can be. In addition, it becomes possible to prepare a stable positive control solution or standard solution containing human hemoglobin and control the accuracy of the measured values.

Claims (15)

[Claims] 1. A method for stabilizing human hemoglobin in a solution, the method comprising selecting human hemoglobin and casein, boric acid or a salt thereof, an aluminum salt, thiourea, calcium chloride and calcium acetate. A method in which a species or two or more species coexist in a solution. 2. The two or more substances are casein and at least one substance selected from the group consisting of boric acid or a salt thereof, an aluminum salt, thiourea, calcium chloride and calcium acetate. 2. The method according to 1. 3. The method according to claim 2, wherein the at least two substances are boric acid or a salt thereof, and at least one selected from the group consisting of an aluminum salt, thiourea, calcium chloride and calcium acetate.
The method of claim 1, wherein the method is a species material. 4. The method according to claim 1, wherein the pH of the solution is in the range of 5.5 to 7.5. 5. Dissolving a substance containing human hemoglobin containing one or more substances selected from the group consisting of casein, boric acid or a salt thereof, an aluminum salt, thiourea, calcium chloride and calcium acetate. Buffer for 6. The two or more substances are casein and at least one substance selected from the group consisting of boric acid or a salt thereof, an aluminum salt, thiourea, calcium chloride and calcium acetate. 5. The buffer according to 5. 7. The buffer according to claim 5, wherein the two or more substances are boric acid or a salt thereof and at least one substance selected from an aluminum salt, thiourea, calcium chloride, and calcium acetate. . 8. The buffer according to claim 5, wherein the pH of the buffer is in the range of 5.5 to 7.5. 9. The buffer according to claim 5, wherein the substance containing human hemoglobin is human feces. 10. A human hemoglobin-containing human hemoglobin comprising human hemoglobin and one or more substances selected from the group consisting of casein, boric acid or a salt thereof, an aluminum salt, thiourea, calcium chloride and calcium acetate. solution. 11. The method according to claim 11, wherein the two or more substances include casein,
At least one selected from boric acid or a salt thereof, an aluminum salt, thiourea, calcium chloride, and calcium acetate
The human hemoglobin-containing solution according to claim 10, which is a species substance. 12. The human hemoglobin according to claim 10, wherein the two or more substances are boric acid or a salt thereof and at least one substance selected from an aluminum salt, thiourea, calcium chloride, and calcium acetate. Containing solution. 13. The human hemoglobin-containing solution according to claim 10, wherein the pH of the buffer is in the range of 5.5 to 7.5. 14. The human hemoglobin-containing solution according to claim 10, wherein the human hemoglobin-containing solution is a human hemoglobin positive control solution or a human hemoglobin standard solution. 15. A buffer for dissolving a substance containing human hemoglobin, comprising one or more substances selected from the group consisting of casein, boric acid or a salt thereof, an aluminum salt, thiourea, calcium chloride and calcium acetate. A stool container for measuring human hemoglobin, comprising: