GB/T 21174-2007Determination of beta-Lactams residues in animal derived food - Radio-receptor assay method (English PDF)

3.1 Sample Preparation

Was removed from the original sample portion representative sample should be as fat removed. The edible part of the organization into a high-speed machines are broken

Quality, thoroughly mixed, and dividing by quartering a sample of not less than 500g. Load a clean container and labeled markers.

Sample number of bacteria in the sample preparation procedure should prevent sample contamination or the occurrence of the change of residue content, for the determination not exceed

106/g.

3.2 Sample preservation

The following sample at -18 °C preservation, fresh or frozen tissue samples can be stored 72h at 2 °C ~ 6 °C.

4.1 Principle

Based assay is the continuity of the receptor immunoreactivity in samples of residual beta- lactams and [

14C] labeled penicillin G, respectively

Specific receptor binding of microbial cells. The sample was measured by scintillation counting of [. 14C] Content count value (cpm), the count value with a liquid

And sample beta- lactams residues in inverse proportion.

4.2 Reagents and materials

Unless otherwise indicated, the reagents used were of analytical grade water as a water GB/T 6682 regulations.

4.2.1 CharmII organization beta- lactams assay kit

1).

1) CharmII organization beta- lactams assay kit and CharmII liquid scintillation counter is provided by the company's products CharmScience

Trade names. This information is given for the convenience of users of this standard does not imply endorsement of the product. If other equivalent products with the same

Effect, you can use these equivalent products.

4.2.1.1 negative control concentrated powder

Store at 2 °C ~ 6 °C. When dissolved in water by using 10mL to prepare a negative tissue fluid. Negative group

Tissue fluid can be stored at 2 °C ~ 6 °C in 48h. Such a long time, can be stored frozen at -15 °C the following two months, the use of which thawed solution

After freeze solution can be stored at 2 °C ~ 6 °C 24h.

4.2.1.2 MSU variety of antibiotics Standard

stored at 2 °C ~ 6 °C. Dissolved in 10mL of water when used to prepare a variety of anti-MSU Standard antibiotic solution (penicillin G wherein the concentration of 1000µg/L). MSU variety of antibiotics preservation method with standard solutions 4.2.1.1.

4.2.1.3 MSU extraction buffer concentrate powder

dissolving when using 1000mL of water, formulated as MSU extraction buffer, in […]