Summary of the invention
The object of the present invention is to provide the residual fluorescence polarization immunologic detection method of a kind of fast detecting bisphenol-A, and higher sensitivity and specificity are arranged.
Technical scheme of the present invention: a kind of fluorescence polarization immunoassay detection method of bisphenol-A, utilize diphenolic acid as the synthesizing fluorescently labeled thing of hapten conjugation FITC fluorescein derivative, and be standard items with the bisphenol-A, resist with bisphenol-A is antibody more, sets up the fluorescence polarization immunoassay detection method of bisphenol-A; Step is as follows:
(1) preparation of FITC fluorescein derivative EDF:
Measure the 200mg ethylenediamine-hydrochloride respectively, 500 μ L triethylamines are dissolved in the methyl alcohol of 50mL, must contain the triethylamine solution of ethylenediamine-hydrochloride;
The fluorescein FITC of 117mg, the triethylamine of 100 μ L is dissolved in the methyl alcohol of 10mL, gets FITC solution;
Dropwise the FITC drips of solution is added and contain in the triethylamine solution of ethylenediamine-hydrochloride;
Mixed dissolution, stirring reaction 10h under the room temperature lucifuge filters to isolate precipitation then, and drying gets FITC fluorescein derivative (EDF), keeps in Dark Place;
(2) preparation of EDF label:
N-hydroxy-succinamide NHS 9.2mg, dicyclohexylcarbodiimide DCC16.4mg and diphenolic acid 1.4mg are dissolved among the DMF of 2.0mL, stir under the room temperature and spend the night;
Add the derivant EDF 2-3mg of the fluorescein-labelled thing of FITC in reaction solution, lucifuge stirring reaction 3h makes the EDF label under the room temperature;
(3) purifying of EDF label:
With CHCl
3/ MeOH=1:1 is a developping solution, carries out thin-layer chromatography under the room temperature, separation and purification EDF label, and ultraviolet transilluminator is observed down, selects R
f=0.56 band is with 300 μ L methanol extractions;
(4) determining of EDF label working concentration:
With the EDF label of 0.025M, pH8.0 borate buffer solution dilution variable concentrations, last polarimeter detection intensity of polarization light, with 10 times of intensity of polarization light to blank solution as its working concentration; Determine to choose the 1:1500 dilution as working concentration; Blank solution is selected 0.025M, pH8.0 borate buffer solution for use;
(5) determining of the bisphenol-A working concentrations that resist more:
In each test tube, add 500 μ L successively and be diluted to different dilute concentrations: 1:200 with 0.025M, pH8.0 borate buffer solution, 1:400,1:800,1:1600,1:3200,1:6400, how anti-the bisphenol-A of 1:12800 is, and add the EDF label of 500 μ L successively, hatches 5min under the room temperature, last polarimeter detects the polarization light value, determines to choose the working concentration of 1:800 dilution as antibody;
(6) competition:
Bisphenol-A is diluted to 1,5,25,125,625,3125,15625 with ultrapure water, and the 78125ng/mL series concentration adds respectively in the different test tubes, and other establishes a ultrapure water blank, 50 μ L/ pipe; Add the EDF label of 1500 times of 500 μ L dilutions then in each test tube, the bisphenol-A that adds 800 times of 500 μ L dilutions at last respectively resists under room temperature more hatches 5min, and last polarimeter detects the polarization light value;
(7) standard of setting up bisphenol-A suppresses logarithmic curve: with measured detection polarization light value is ordinate, is the standard inhibition logarithmic curve that bisphenol-A is set up in the horizontal ordinate mapping with the bisphenol A concentration;
(8) detection of actual sample: with actual sample set by step the method for (6) detect, the polarization light value that records suppresses the logarithmic curve contrast with the standard of bisphenol-A, determines the bisphenol-A residual concentration of sample.
More detailed step is:
Main solution preparation
1) preparation 0.025M, pH8.0 borate buffer solution:
Na
2B
4O
710H
2O 9.534 g add ultrapure water and are diluted to 980 mL, transfer to pH8.0 with 2M NaOH, add ultrapure water and are settled to 1000 mL.
The step of fluorescence polarization immunoassay detection method is as follows:
The methanol solution that in advance standard items of bisphenol-A is mixed with 1mg/mL is as the work mother liquor, and is stand-by 4 ℃ of preservations.Preparation borate buffer solution (0.025mol/L, pH8.0) is prepared serial reaction liquid based on this, and is how anti-in order to dilute fluorescein-labelled thing and bisphenol-A.
Determining of a, fluorescein-labelled thing working concentration: the fluorescein-labelled thing of dilution variable concentrations, last machine testing intensity of polarization light, with 10 times of intensity of polarization light to blank solution (0.025M, pH8.0 borate buffer solution) as its working concentration.Experimental result is chosen 1:5000 as working concentration.
Determining of the working concentration of b, bisphenol-A antibody: in each test tube, add 500 μ L are diluted to different dilute concentrations with 0.025M, pH8.0 borate buffer solution bisphenol-A antibody (1:200 successively, 1:400,1:800,1:1600,1:3200,1:6400,1:12800), and add the fluorescein-labelled thing of 500 μ L successively, hatch 5min under the room temperature, last machine testing polarization light value.Experimental result is chosen the working concentration of 1:800 as antibody.
C, competition:
Bisphenol-A is diluted to 1,5,25,125,625,3125,15625 with ultrapure water, and the 78125ng/mL series concentration adds respectively in the different test tubes, and other establishes a ultrapure water blank, 50 μ L/ pipe.The fluorescein-labelled thing that adds 1500 times of 500 μ L dilutions then in each test tube, how anti-the bisphenol-A that adds 800 times of 500 μ L dilutions at last respectively is, hatches 5min under room temperature.
D, mensuration: go up machine testing polarization light value.
Beneficial effect of the present invention: the present invention has set up bisphenol-A fluorescence polarization immunologic detection method, for the bisphenol-A residue detection provides a kind of detection means rapidly and efficiently, because employing is polyclonal antibody and portable fluorescence polarization instrument, expense is lower, fast, convenient, reliable.Sensitivity is 2ng/mL, and the range of linearity is 20-800ng/mL.Immunoreactive high specific and high-affinity make the fluorescence polarization immunity have high selectivity and sensitivity, and sample pre-treatment process is simple, and is easy to operate, fast.
Specific embodiments
Further specify the present invention by the following examples.
One, instrument:
The KFLOW water purification machine, Kai Folong company,
AB104-N type electronic analytical balance,
Portable fluorescence polarization instrument, SENTARY 100,
Can debug pipettor, Thermo Labsystems company,
Turbine mixer, Shanghai Hu Xi instrumental analysis factory.
Two, reagent:
The bisphenol-A polyclonal antibody, the laboratory self-control,
Other reagent are analytical reagent.
Three, step
1.FITC the preparation of fluorescein derivative (EDF), step is as follows:
Measure the 200mg ethylenediamine-hydrochloride respectively, 500 μ L triethylamines are dissolved in the methyl alcohol of 50mL, must contain the triethylamine solution of ethylenediamine-hydrochloride.
The fluorescein FITC of 117mg, the triethylamine of 100 μ L is dissolved in the methyl alcohol of 10mL, gets FITC solution.
Dropwise the FITC drips of solution is added and contain in the triethylamine solution of ethylenediamine-hydrochloride.
Mixed dissolution, stirring reaction 10h under the room temperature lucifuge filters to isolate precipitation then, and drying gets FITC fluorescein derivative (EDF), keeps in Dark Place.
2.EDF the preparation of label, step is as follows:
N-hydroxy-succinamide (NHS) (9.2mg, 80 μ mol), dicyclohexylcarbodiimide (DCC) (16.4mg, 80 μ mol), and diphenolic acid (1.4mg, 4.8 μ mol) is dissolved among the DMF of 2.0mL.Stir under the room temperature and spend the night.
Add the derivant EDF2-3mg of the fluorescein-labelled thing of FITC in reaction solution, lucifuge stirring reaction 3h makes the EDF label under the room temperature.
3, the purifying of EDF label:
With CHCl
3/ MeOH=1:1 is a developping solution, carries out thin-layer chromatography under the room temperature, separation and purification EDF label.Ultraviolet transilluminator is observed down, selects R
f=0.56 band.With 300 μ L methanol extractions.
4, determining of EDF label working concentration:
With the EDF label of 0.025M, pH8.0 borate buffer solution dilution variable concentrations, last machine testing intensity of polarization light, with 10 times of intensity of polarization light to blank solution (0.025M, pH8.0 borate buffer solution) as its working concentration.Experimental result is chosen 1:1500 as working concentration.
5, determining of the working concentration of bisphenol-A antibody:
In each test tube, add 500 μ L successively and be diluted to the bisphenol-A antibody (1:200 of different dilute concentrations with 0.025M, pH8.0 borate buffer solution, 1:400,1:800,1:1600,1:3200,1:6400,1:12800), and add the EDF label of 500 μ L successively, and hatch 5min under the room temperature, last polarimeter detects the polarization light value.Experimental result is chosen the working concentration of 1:800 as antibody.
6, competition:
Bisphenol-A is diluted to 1,5,25,125,625,3125,15625 with ultrapure water, and the 78125ng/mL series concentration adds respectively in the different test tubes, and other establishes a ultrapure water blank, 50 μ L/ pipe.Add the EDF label of 1500 times of 500 μ L dilutions then in each test tube, the bisphenol-A that adds 800 times of 500 μ L dilutions at last respectively resists under room temperature more hatches 5min.Last polarimeter detects the polarization light value.
Test findings is as follows:
1, typical curve: the range of linearity of the antibody test that the present invention obtained is to be 20~800ng/mL.
2, sensitivity: sensitivity is the concentration of the pairing standard items of gained 90% maximum polarization light value, i.e. IC
10Be 2ng/mL.