1. Principle

The BIOKAU^® Diethylstilbestrol ELISA Test Kit is based on the competitive enzyme immunoassay for the detection of Diethylstilbestrol (DES) in the feed, urine, liver, meat, shrimp and fish. The conjugate antigen is pre-coated on the micro-well stripes. The Diethylstilbestrol in the sample competes with the conjugate antigen pre-coated on the micro-well stripes, to interact with the antibodies against Diethylstilbestrol. After the addition of the enzyme conjugate, the TMB substrate is added for coloration. The optical density (OD) value of the sample has a negative correlation with the content of Diethylstilbestrol in the sample. This value is compared to the standard curve and the content of the corresponding Diethylstilbestrol is subsequently obtained.

2. Technical specifications

Sensitivity: 0.1 ppb

Detection limit

Shrimp, fish.................................................................................. 0.2 ppb

Pork/liver, chicken/liver...................................................................... 2 ppb

Urine............................................................................................. 0.6 ppb

Feed.............................................................................................. 20 ppb

Recovery rate

Urine............................................................................................ 70 ±10%

Feed............................................................................................ 90 ±10%

Tissue.......................................................................................... 85 ±10%

Cross-reactions rate

DES................................................................................................ 100%

Dienestrol....................................................................................... 38.5%

Hexestrol.......................................................................................... 8.5%

Ethinylestradiol.............................................................................. < 0.1%

Estriol............................................................................................ < 0.1%

3. Components

1）   Micro-well strips: 12 strips with 8 removable wells each

2）   6 × standard solution (1 mL each): 0 ppb, 0.1 ppb, 0.3 ppb, 0.9 ppb, 2.7 ppb, 8.1 ppb

3）   Enzyme conjugate (12 mL)............................................................. red cap

4）   Antibody working solution (7 mL).................................................. blue cap

5）   Substrate A solution (7 mL).......................................................... white cap

6）   Substrate B solution (7 mL)......................................................... black cap

7）   Stop solution (7 mL).................................................................. yellow cap

8）   20× concentrated washing buffer (40 mL)..................................... white cap

9）   5× concentrated redissolving solution (50 mL)..................... transparent cap

4. Materials required but not provided

1)      Equipments: microplate reader, printer, homogenizer, nitrogen-drying device, votex, centrifuge, measuring pipets, balance (a sensibility reciprocal of 0.01 g)

2)      Micropipettors: single-channel 20-100 µL ,100-1000 µL, and multi-channel 250 µL;

3)      Reagents: NaOH, Acetonitrile (CH₃CN), Acetone, deionized water, H₃PO₄ (85%), CHCl₃