LSY-10060 Avermectin ELISA Test Kit milk testing, shrimp safety, meat inspection ISO certificate

Avermectin ELISA Test Kit

Catalog No. LSY-10060

1. Principle

This test kit is based on the competitive enzyme immunoassay for the detection of Avermectin in the sample. The coupling antigens are pre-coated on the micro-well stripes. The Avermectin in the sample and the coupling antigens pre-coated on the micro-well stripes compete for the anti-Avermectin antibodies. 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 Avermectin in it. This value is compared to the standard curve and the Avermectin concentration is subsequently obtained.

2. Technical specifications

Sensitivity: 0.5ppb

Detection limit

Tissue............................................................................................ 4ppb

Liquid milk....................................................................................... 5ppb

Shrimp......................................................................................... 0.5ppb

Note: ppb= ng/ml or ng/g

Cross-reaction rate

Avermectin...................................................................................... 100%

Ivermectin......................................................................................... 25%

Eprinomectin..................................................................................... 10%

Doramectin......................................................................................... 6%

Recovery rate

90±30%

3. Components

1. Micro-well strips: 12 strips with 8 removable wells each
2. 6× standard solution (1mL each): 0ppb,0.5ppb,1.5ppb, 4.5ppb,13.5ppb,40.5ppb
3. 11X Concentrated Enzyme conjugate (0.7 mL)
4. Enzyme conjugate dilution (7 mL)
5. Substrate A (7 mL)
6. Substrate B (7 mL)
7. Stop solution (7 mL)
8. 20× concentrated washing buffer (30 mL)
9. Redissolving solution (50 mL)
10. Tissue sample treatment solution (10mL)

4. Materials required but not provided

1. Equipments: microplate reader (450nm, 630nm), printer, homogenizer, nitrogen-drying device, vortex, shaker, centrifuge (4000g and above), measuring pipets, balance (a reciprocal sensibility of 0.01 g), incubator (25℃), timer;
2. Micropipettors: single-channel 20-200 µL, 100-1000 µL, and eight-channel 30～300 µl;
3. Reagents (AR): Methanol, deionized water,N-hexane, Na2SO4, Acetonitrile.

5. Sample pre-treatment

Instructions

The following points must be dealt with before the pre-treatment of any kind of sample:

1. Only the disposable tips can be used for the experiments and the tips must be changed when used for absorbing different reagents;
2. Before the experiment, each experimental equipment must be clean and should be re-cleaned if necessary, in order to avoid the contamination that interferes with the experimental results.

Solution preparation before sample pre-treatment:

Washing buffer: 1 part 20× concentrated washing buffer + 19 parts deionized water.

5.1 Tissue

1) Take 2.0±0.05g homogenized tissue sample into a 10ml Polystyrene centrifuge tube;

2) Add 2ml Methanol, 100ul Tissue sample treatment solution accordingly, vortex for 5min until tissue sample separate;

3) Centrifuge at 4000g at room temperature (25±2℃) for 10min;

4) Take 200ul up-layer clear liquid, add 400ul redissolving solution, vortex for 10S and mix evenly;

5) Take 50 µL for analysis.

Fold of dilution of the sample: 6

5.2 Milk

1) Take 1ml milk sample into a 10ml Polystyrene centrifuge tube;

2) Add 3ml Methanol, vortex for 1min;

3) Centrifuge at 4000g at room temperature (25±2℃) for 10min;

4) Take 200ul up-layer liquid, add 400ul redissolving solution, vortex for 10S and mix evenly;

1. Take 50 µL for analysis.

Fold of dilution of the sample: 10

5.3 Shrimp

1) Take 2.0±0.1g homogenized tissue sample into a 50ml Polystyrene centrifuge tube;

2) Add 2mL N-hexane, 2mL Acetonitrile accordingly, after vortex one by one quickly, vortex for 1min at high speed;

3) Then add 2g Na2SO4, 4mL Acetonitrile, vortex for 1min at high speed;

4) Centrifuge at 4000g at room temperature (25±2℃) for 10min, discard up-layer N-hexane;

5) Take 2mL up-layer clear liquid into 10mL glass centrifuge tube, blow to dry by Nitrogen at 60℃ water bath, add 0.5mL redissolving solution, vortex for 2min at high speed;

(Note: if there is no glass centrifuge tube, can take 1mL up-layer clear liquid into 4mL clean plastic centrifuge tube, blow to dry by Nitrogen at 60℃ water bath, add 0.5mL redissolving solution, vortex for 1min at high speed, Ultrasound for 10min, continue to vortex for 1min at high speed);

6) Take 50 µL for analysis.

Fold of dilution of the sample: 1

6. ELISA procedures

Instructions

1. Bring all reagents and micro-well strips to the room temperature (20-25 ℃).

2. Return all reagents to 2-8 ℃ immediately after use.

3 .The reproducibility of the ELISA analysis, to a large degree, depends on the consistency of plate washing. The correct operation of plate washing is the key point in the procedures of ELISA.

4. For the incubation at constant temperatures, all the samples and reagents must avoid light exposure, and each microplate should be sealed by the cover membrane.

Operation procedures

1. Take out all the necessary reagents from the kit and place at the room temperature (20 to 25 ℃) for at least 30 minutes. Note that each liquid reagent must be shaken to mix evenly before use.
2. Take the required micro-well strips and plate frames. Re-sealed the unused microplate, stored at 2-8 ℃, not frozen.
3. Numbering: number the micro-wells according to samples and standard solution; each sample and standard solution should be performed in duplicate; record their positions.
4. Enzyme conjugate preparation: take 1 part 11X Concentrated Enzyme conjugate, add 10 parts Enzyme conjugate dilution, dilute at 1:10, get the ready to use Enzyme conjugate.
5. Add 50µL of the sample or standard solution to separate duplicate wells, then add enzyme conjugate, 50 µL each well. Mix gently by shaking the plate manually, seal the microplate with the cover membrane, and incubate at 25 ℃ at dark for 30 minutes.
6. Pour liquid out of microwell, add 300 µL/well of washing buffer for 15-30 seconds, repeat four to five times, then flap to dry (if there are the bubbles after flapping, cut them with the clean tips).
7. Coloration: add 50 µL of the substrate A, then add 50uL of the substrate B into each well. Mix gently by shaking the plate manually, and incubate at 25 ℃ for 15 minutes at dark for coloration.
8. Determination: add 50 µL of the stop solution into each well. Mix gently by shaking the plate manually. Set the wavelength of the microplate reader at 450 nm to determine the OD value (Recommend to read the OD value at the dual-wavelength 450/630 nm within 5 minutes).

7. Result judgment

Quantitative determination

The mean values of the absorbance values is equivalent to the percentage of the average OD value (B) of the sample and the standard solution divided by the OD value (B₀) of the first standard solution (0 standard) and subsequently multiplied by 100%, that is,

B—the average (double wells) OD value of the sample or the standard solution

B₀—the average OD value of the 0 ng/mL standard solution

Draw the standard curve with the absorption percentages of the standard solutions and the semilogarithm values of the Avermectin standard solutions (ng/mL) as Y- and X-axis, respectively. Read the corresponding concentration of the sample from the standard curve by incorporating its absorption percentage into the standard curve. The resulting value is subsequently multiplied by the corresponding dilution fold, thus finally obtaining Avermectin concentration in the sample.

8.Precautions

1). The room temperature below 20 ℃ or the temperature of the reagents and the samples being

not returned to the room temperature (20-25 ℃) will lead to a lower standard OD value.

2). Dryness of the microplate in the washing process will be accompanied by the situations

including the non-linear standard curves and the undesirable reproducibility; So continue to next

step immediately after washing.

3). Mix evenly before adding any reagents.

4). The stop solution is the 2 M sulfuric acid solution, avoid contacting with the skin.

5). Do not use the kit exceeding its expiry date. The use of diluted or adulterated reagents from the

kits will lead to the changes in the sensitivity and the detecting OD values. Do not exchange the

reagents from the kits of different lot numbers to use.

6). Storage: store at 2-8 ℃, not frozen. Put the unused microplate into an auto-sealing bag to

re-seal it. The standard substance and the colourless color former is light sensitive, and thus they

cannot be directly exposed to the light.

7). Discard the colouration solution with any color that indicates the degeneration of this solution.

The detecting value(450/630nm) of the 0 standard solution (0 ppb) of less than 0.5((A450nm<0.5))

indicates its degeneration.

8). After adding substrate, the color reaction time is 15min. If the color is too light, can extend the time to 20min(or longer),but not beyond 30min; otherwise, shorten the reaction time.

8). The optimum reaction temperature is 25 ℃, and too high or too low temperatures will result in

the changes in the detecting sensitivity and OD values.

9. Storage and expiry date

Storage: store at 2-8 ℃, not frozen.

Expiry date: 12 months; date of production is on box.

Shenzhen Lvshiyuan Biotechnology Co., Ltd

D Building, National Biological Industrial Park of Marinelife, No.2 Binhai Road, Dapeng, Shenzhen, 518120 China

Tel. 86-755-28438788

Fax 86-755-28938800

Email: info@lsybt.com

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