JPH085634A - Aqueous solution containing antigen - Google Patents

Abstract

PURPOSE:To realize a long shelf life while sustaining the safety by adding an antigen into an aqueous solution principally comprising casein and whey protein thereby suppressing the devitalization even in the aqueous solution. CONSTITUTION:Casein includes casein in milk, e.g. alpha-casein or lambda-casein, and the concentration is normally set in the range of 0-2.00W/V%. Whey protein includes whey protein in milk, e.g. concentrated whey, and the concentration is normally set in the range of 0-1.00W/V%. Since casein and whey protein coexist, the shelf life stability of aqueous solution containing antigen can be enhanced furthermore. The concentration is preferably set in the range of 0.03-2.00W/V% for casein and in the range of 0.01-1.00W/V% for whey protein. The antigen includes hormone, e.g. insulin, enzymes, antibody and virus. Hormone is employed preferably and insulin is employed more preferably.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the use of an antigen in a standard solution containing an antigen to be used in immunoassays such as enzyme immunoassay, radioimmunoassay or immunoturbidimetry in the field of clinical examination. The present invention relates to an aqueous solution which can prevent deactivation and can be stably stored.

[0002]

2. Description of the Related Art When performing an immunoassay, a standard solution containing an antigen is used. Since the antigen in this standard solution is diluted, some antigens are significantly inactivated in the solution. In particular, the inactivation of antigens such as hormones and enzymes is severe. Conventionally, in order to stably store such a highly inactivated antigen, a method has been used in which water is removed by freeze-drying or the like to be stored as a solid, and then water is added to dissolve the solid at the time of use. .

[0003]

However, although the standard prepared by the conventional freeze-drying method has good storage stability, it is necessary to add water at the time of use to dissolve the solid antigen. Is complicated and a density error is likely to occur. Furthermore, after dissolution, the antigen in the aqueous solution is inactivated, and a concentration error is likely to occur. Therefore, as a result of studying a standard in a solution state without a preparation operation of dissolving by adding water, improvement in adding proteins such as bovine serum albumin and serum to an antigen-containing aqueous solution was performed. However, even with these improvements, there is a problem that storage stability cannot be maintained for a long period of one year or more.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, by containing an antigen in an aqueous solution containing casein and / or whey protein as a main component, an aqueous solution containing The present inventors have found an aqueous solution containing an antigen which has a small inactivation of the antigen and can maintain the storage stability for a long period of one year or more, and reached the present invention.

That is, the present invention is an antigen-containing aqueous solution comprising an antigen and casein and / or whey protein.

The casein in the present invention includes casein in milk. For example, casein described in the “Fifth Edition Food Additive Official Standard Manual (issued by Hirokawa Shoten)” can be used. Specific examples include α-casein, β-casein, γ-casein, κ-casein, and λ-casein. The concentration of casein is usually 0 to 2.00
w / v%, preferably 0.05 to 0.25 w / v%.

Examples of whey protein include whey protein in milk. Examples of whey proteins include concentrated whey and whey powder described in “Ministry Ordinance on Ingredients for Milk and Dairy Products in the Food Sanitation Law”. The concentration of whey protein is usually 0 to 1.00 w / v%, preferably 0.03 to 0.15 w / v%.

[0008] By coexisting casein and whey protein, the storage stability of the aqueous solution containing the antigen can be further improved. The concentration at this time was 0.03 casein.
~ 2.00 w / v%, whey protein 0.01 ~ 1.00 w
/ V%, particularly preferably 0.05% casein.
~ 0.25w / v%, whey protein 0.03 ~ 0.15w
/ V%.

[0009] Antigens include hormones, enzymes, antibodies and viruses. Insulin as insulin,
Thyroid stimulating hormone (TSH), follicle stimulating hormone (F
SH), human chorionic gonadotropin (hCG), luteinizing hormone (LH), prolactin and the like. Examples of the enzyme include nerve-specific enolase (NSE). Examples of the antibody include IgE. Examples of viruses include HBs. Of these, hormones are preferred, and insulin is more preferred.

[0010]

The present invention will be further described with reference to the following examples, but the present invention is not limited to these examples. Example Storage stability of insulin standard solution a) Preparation of insulin standard solution containing casein and whey protein as main components Concentration of 0.06 w / v% casein (made by milk), 0.03
w / v% whey protein (made of milk), 0.1 w / v% NaN
3. Insulin was added to a 0.02 M aqueous phosphate buffer solution containing 0.9 w / v% NaCl, and 10 μg / ml and 50 μm
g / ml, 125 μg / ml, and 250 μg / ml of insulin standard solution A were prepared. b) Preparation of insulin standard solution containing bovine serum albumin (BSA) as a main component. The concentration was 1 w / v% BSA, 0.1 w / v% NaN3,
Insulin was added to a 0.02 M phosphate buffer aqueous solution containing 0.9% NaCl, and 10 μg / ml, 50 μg / ml,
Insulin standard solutions B of 125 μg / ml and 250 μg / ml were prepared. c) Examination of storage stability Insulin standard solutions A and B at each concentration were stored at 4 ° C. and 25 ° C., and at the time of preparation, the insulin concentrations at 1 month, 3 months, 6 months, and 12 months were determined by Glyzyme Insulin.
(Manufactured by Sanyo Kasei Co., Ltd.) to measure changes in insulin concentration. The results are shown in Table 1.

[0011]

[Table 1]

As can be seen from Table 1, insulin standard solution A
Insulin concentration of No. 2 was stable over 12 months and was stable after 12 months, but the insulin concentration of insulin standard solution B decreased with time.

[0013]

According to the method for stably storing an antigen-containing solution of the present invention, antigens with severe inactivation such as hormones and enzymes can be stably stored in solution for a long period of one year or more. For this reason, the stability can be maintained for a long time without lyophilization, which has been conventionally performed, and the error in concentration caused by the complicated preparation operation of dissolving the antigen has been eliminated, so that immunoassay with good accuracy and reproducibility can be performed. Now you can. In view of the above, the present invention can be applied to standard solutions of hormones, enzymes, antibodies and viruses, which are particularly severe in antigen deactivation, and can obtain clinical test measurement values with high accuracy and reproducibility since there is no concentration change. .

Claims (4)

[Claims] 1. An antigen-containing aqueous solution comprising an antigen and casein and / or whey protein. 2. The casein concentration in the antigen-containing aqueous solution is 0 to 2.
2.00 w / v%, whey protein concentration 0-1.00 w /
The aqueous solution according to claim 1, which is v%. 3. The aqueous solution according to claim 1, wherein the antigen is a hormone. 4. The aqueous solution according to claim 1, wherein the antigen is insulin.