How to choose the right control materials

How to choose the right control materials

Internal Quality control is a series of checks and controls adopted by laboratories through the daily determination of control materials to control the changes in precision and accuracy of laboratory tests, monitoring and evaluating the quality of the work of the laboratory to determine whether the routine test report can be issued. Therefore, the selection of control materials is particularly important.


Classification of control materials

1. Supporting control materials

Control materials produced by the reagent manufacturer for the reagent supporting the plant, generally can only be used for supporting reagents.

2. Third-party control materials

Produced by a third-party manufacturer that does not belong to the instrument manufacturer or the reagent manufacturer, not specifically for a particular instrument or method and reagent supporting the production of, such as Randox QC, Bio-Rad QC.

3. Internal control materials

Laboratory's own preparation of control materials.


Comparison of the advantages and disadvantages of various types of control materials

Classification of control materials

Supporting control materials

Third-party control materials

Internal control materials


1. The matching is good.

2. Control value is generally more reasonable.

3. Fixed value between-run precision is small.

1. High degree of composite, relatively cheap.

2. Longer validity period, stable batch number change.

3. Objective, high recognition.

4. Widely used, can be applied to different instruments and methods, good adaptability.

1. The price of finished products is relatively low

2. Can make up for the shortcomings of not being able to purchase commercialized quality control products.


1. Short validity period, batch number changes frequently.

2. The degree of composite is not high enough, and the relative price is relatively expensive.

3. Evaluation objectivity is not enough.

1. Control values are generally not suitable for all items.

2. It is necessary for laboratories to find suitable products by themselves.

1. Shelf life is shorter, stability can not be guaranteed.

2. The fixed value is more frequent, and the difference in value between batches is large.


Comparison of the advantages and disadvantages of control materials in different states of preservation

Classification of control materials

Liquid stored at 2-8°C

Liquid storage by freezing (below -20°C)

Cryopreservation of lyophilized powder


1. Easy to use, can be used directly

2. Long validity period after opening the bottle

3. Test value is stable

4. Low transportation requirements, easy to store

1. No need to re-dissolve, easy to use

2. Many varieties available

1. The cost is relatively low

2. Many varieties available


1. Fewer varieties available

1. Requires low-temperature transportation

2. Some items have a short shelf life

1. Shelf life is shorter after re-solubilization, stability can not be guaranteed

2. Between-bottle homogeneity are large


Characteristics of ideal control materials

Human serum matrix;

Uniformly distributed;


Low quantities of additives and modifiers;

Low Between-bottle homogeneity;

Lyophilized products remain stable after reissolution;

Shelf life of more than 1 year.

Each laboratory can choose according to its own situation and according to its own requirements.


保方.浅谈生化室内质量控制 .第二届全国生化仪应用研讨会,103-104.

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