Ochratoxin A Colloidal Gold Rapid Detection Card

Ochratoxin A Colloidal Gold Rapid Detection Card

operation instructions

(Colloidal gold method)

1. Principle and Application

This product is made by the principle of competitive inhibition colloidal gold immunochromatography, and is used to detect Ochratoxin A (OTA) residues in grains, feedstuffs and other samples.

After the sample solution is dropped into the sample adding hole of the detection card, the Ochratoxin in the sample solution combines with the gold labeled antibody, thus preventing the gold labeled antibody from combining with the Ochratoxin conjugate on the cellulose membrane. When the Ochratoxin content in the sample solution is greater than the detection limit, the detection line does not show color (or the color is lighter than the control line), and the result is positive; When the content of Ochratoxin in the sample solution is less than the detection limit, the detection line appears purplish red (the color is consistent with or deeper than the control line), and the result is negative.

2. Technical indicators

2.1 Sensitivity of reagent card: 5ppb (ng/ml)

2.2 Lower limit of sample detection:

Cereals, feed, etc. 5 ppb

3. Kit composition

Detection card: 40 pieces/box

Instructions: 1 copy

Sample duplicate solution: 1 bottle

4. Required equipment and reagents

4.1 Instruments: homogenizer, oscillator, centrifuge, graduated pipette, balance (sensitivity 0.01g)

4.2 Micro Pipette: single channel 20 µ l-200 µ l, 100 µ l-1000 µ l

4.3 Reagent: None

5. Sample pretreatment

Cereals, feed

1) Take more than 5g of representative feed and grain samples (rice, wheat, corn, peanuts) and crush them (through a 20 mesh sieve). Accurately weigh 2g of the crushed sample and place it in a matching 15ml centrifuge tube.

2) Accurately add 3ml of extraction agent (ethyl acetate) to a 15ml centrifuge tube, tightly seal the bottle stopper, shake vigorously for 3 minutes, and centrifuge at 4000rpm for 3 minutes.

3) Take 1mL of the layered supernatant from a 15ml centrifuge tube with a pipette and transfer it to a matching 5ml centrifuge tube. Blow dry with nitrogen or a hair dryer (some yellow grease on the bottom layer is normal). Add 0.3ml (about 10 drops with a matching dropper) of the matching sample solution to the dried 5ml centrifuge tube, and dissolve the solid residue at the bottom and inner wall of the centrifuge tube. This solution is the test solution.

6. Experimental Steps

1) Tear open the aluminum foil packaging bag of the detection card, take out the reagent board, and place it on a flat and clean surface.

2) Take 150ul of the prepared sample solution to be tested and add it to the gold standard well. Wait for 2 minutes for the reaction, blow with a dropper until the purple red substance in the well is completely dissolved, and wait for 2 minutes. Take 120ul of the solution in the well and add it to the sample well. After adding the sample, start timing;

3) Leave at room temperature for 5-8 minutes to determine the results, but after 30 minutes, the interpretation of the results is invalid.

7. Result judgment

Negative: In the detection window, a purple red line appears on the control line (C), and the color of the detection line (T) is consistent with or deeper than the control line, indicating that the concentration in the sample is below the detection limit or does not contain.

Positive: In the detection window, the control line (C) shows a purple red line, while the detection line (T) does not show color or is lighter than the control line. Indicates that the concentration in the sample is above the detection limit.

Invalid: Within the detection window, there is no purple red line on the control line (C).

8. Precautions

8.1 Products that have expired or have damaged aluminum foil bags cannot be used.

8.2 When removing the detection card from the refrigerator, it should be restored to room temperature before opening. The opened detection card should be used as soon as possible to avoid failure due to moisture.

8.3 Do not touch the white film surface in the center of the detection card.

8.4 Droppers should not be mixed to avoid cross contamination.

8.5 The sample solution to be tested should be clear, free from turbid particles, and bacterial contamination, otherwise it may lead to abnormal phenomena such as blockage and unclear color development, which may affect the judgment of experimental results.

9. Storage and shelf life

Storage conditions: The reagent kit should be stored in a dry environment at 2-30 ℃.

Shelf life: The product has a validity period of 1 year, and the production date can be found in the packaging box.