Rapid detection method for ricin toxin
A rapid detection method for ricin toxin is provided. The rapid detection method for ricin toxin comprises reacting an adenine-containing oligonucleotide chain substrate labeled with a fluorescent group and a quenching group, a buffer solution, a BSA solution, a to-be-detected sample and sterile water, incubating at a constant temperature, detecting a fluorescence signal value, and determining whether the ricin toxin exists based on a difference between an average value of final fluorescence signal values and an average value of final fluorescence signal values of a negative control; wherein the sample is judged as a positive sample when the average value of the detected final fluorescence signal values is greater than the average value of the final fluorescence signal values of the negative control by +3 times standard deviation.
1. A detection method for ricin toxin, comprising the following steps:
subjecting an adenine-containing oligonucleotide chain substrate labeled with a fluorescein (FAM) fluorescent group and a Black Hole Quencher 1 (BHQ1) quenching group, a buffer solution, a bovine serum albumin (BSA) solution, a to-be-detected sample, and sterile water to a reaction to obtain a product,
incubating the product at a constant temperature between 55 and 70° C.,
detecting a fluorescence signal value 2-5 times to obtain final fluorescence signal values, and
determining whether the ricin toxin exists based on a difference between an average value of final fluorescence signal values and an average value of final fluorescence signal values of a negative control;
wherein the adenine-containing oligonucleotide chain substrate is a single-stranded DNA sequence consisting of SEQ ID NO: 10 (DNA6A) with a 5′ terminus labeled with the FAM fluorescent group and a 3′ terminus labeled with the BHQ1 quenching group; the adenine-containing oligonucleotide chain substrate has a final concentration of 6-16 μM;
the buffer solution is an ammonium formate buffer solution, an ammonium acetate buffer solution, an ammonium citrate buffer solution, an ammonium acetate and ethylene diamine tetraacetic acid (EDTA) buffer solution, or an ammonium citrate and EDTA buffer solution;
the reaction is performed at a pH value of 3.8-4.6; and
the to-be-detected sample is enriched by using antibody-coated magnetic beads, wherein antibodies for coating the magnetic beads are specific for ricin toxin.
2. The detection method according to claim 1 , wherein an amount of the adenine-containing oligonucleotide chain substrate labeled with the FAM fluorescent group and the BHQ1 quenching group, the buffer solution, the BSA solution, the to-be-detected sample, and the sterile water is 0.5-6 μL, respectively.
3. The detection method according to claim 1 , wherein an amount of the antibodies for coating the magnetic beads is 20-30 μg per 0.5-2 mg of the magnetic beads.
4. The detection method according to claim 1 , wherein the ammonium formate buffer solution, the ammonium acetate buffer solution, and the ammonium citrate buffer solution have a final concentration of 0.2-20 mM, respectively; in the ammonium acetate and EDTA buffer solution, ammonium acetate has a final concentration of 0.2-20 mM, and EDTA has a final concentration of 0.2-0.8 mM; in the ammonium citrate and EDTA buffer solution, ammonium citrate has a final concentration of 0.2-20 mM, and EDTA has a final concentration of 0.2-0.8 mM; and the BSA solution has a final concentration of 10-100 μg/mL.
5. The detection method according to claim 1 , wherein the step of incubating the product is performed for 30-50 min.
6. The detection method according to claim 1 , wherein the to-be-detected sample is judged as a positive sample when the average value of the final fluorescence signal values is greater than the average value of the final fluorescence signal values of the negative control by +3 times standard deviation.