CN101519682B

CN101519682B - Method for detecting cat source components in food and fodder and kit

Info

Publication number: CN101519682B
Application number: CN2009100482234A
Authority: CN
Inventors: 张舒亚; 刘月明; 管薇薇; 李妮
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-03-26
Filing date: 2009-03-26
Publication date: 2012-01-11
Anticipated expiration: 2029-03-26
Also published as: CN101519682A

Abstract

The invention discloses a method for detecting cat source components in food and fodder and a kit. Specifically, the invention discloses a method for quickly detecting cat source components, wherein apolymerase chain reaction is carried out in a polymerase reaction system which contains specific primer pairs of the expanded cat source components and cat source component specific probes. The inven tion also provides a corresponding kit. The method can quickly and conveniently detect and identify the cat source components.

Description

Detection method and kit for cat-derived components in food and feed

Technical Field

The invention relates to the technical field of molecular biology and nucleic acid detection. More particularly, it relates to a method and a kit for rapidly detecting cat-derived components.

Background

In animal product raw materials and processed products, adulteration and unintentional contamination of animal ingredients often occur. Artificial adulteration is mainly a fraudulent act of reducing costs or increasing quality by illegal means in order to earn enormous economic benefits, while in the processing of food and feed, low-priced raw materials are substituted for or incorporated into high-priced raw materials. The fraudulent conduct of adulteration and counterfeiting is prohibited by a plurality of laws and regulations in China.

The adulteration and adulteration act affects the economy of China, and the other one mainly affects the human health and the safety of livestock and poultry. The occurrence and spread of mad cow disease bring great loss to the economy of countries in the world such as European Union, and the transmission path of the mad cow disease is mainly to feed ruminants with mammal-derived feed.

At present, legislation is enacted in various countries such as the European Union, the United states, Japan, etc., and the ruminant is prohibited from being fed with the feed of mammal origin, so as to prevent the occurrence and spread of mad cow disease. In order to completely cut off the transmission path of mad cow disease and prevent the mad cow disease from occurring in China, the Ministry of agriculture in 2002 publishes 'notice about banning the addition and use of animal feed in ruminant feed', and 'methods for managing the safety and health of animal-derived feed products' promulgated and implemented in 2004, and bans the use of mammal-derived ingredients in ruminant feed. Cats are a very large number of animals/pets, a kind of mammal, a kind of human being. If not strictly regulated, the tissue of a dead cat may be used in the processing of animal feed. If animal feed is mixed with animal ingredients of feline origin, the biological risk of an animal's disease outbreak epidemic may be present.

Cats are animals that are not commonly eaten by people, carry common diseases of people and livestock such as rabies, and have the risk of spreading the diseases. If the cat meat which is not eaten frequently is eaten, diseases can be transmitted.

At present, no corresponding method for detecting cat-derived components in food and feed exists in China. That is, the detection of cat-derived ingredients in food and feed is still blank. The establishment of the method for detecting the cat-derived ingredients in the food and the feed has very important significance for fighting against counterfeit and shoddy food and feed, ensuring the rights and benefits of consumers and body health, protecting the safety and economic benefits of animal husbandry in China, avoiding international trade disputes and the like, and is an imminent food safety problem and inspection and quarantine problem to be solved.

In view of the above, there is no detection technology for rapidly and easily detecting and identifying cat-derived components, and there is a strong need in the art to develop a new technology for rapidly and easily detecting and identifying cat-derived components.

Disclosure of Invention

The invention aims to provide a technology for quickly and simply detecting and identifying whether cat-derived ingredients exist in food or feed.

In a first aspect of the present invention, there is provided a polymerase chain reaction method comprising the steps of:

performing polymerase chain reaction in a polymerase reaction system, wherein the reaction system contains a specific primer pair for amplifying cat-derived components and a cat-derived component specific probe, and an amplification product amplified by the primer has a sequence shown as SEQ ID NO: 5, and the cat-derived component specific probe is combined with a nucleotide sequence of a cat mitochondrial 12S rRNA gene shown as SEQ ID NO: 5, the nucleotide sequence of the cat mitochondrial 12S rRNA gene.

In another preferred class, the feline-derived component-specific probe has the amino acid sequence of SEQ ID NO: 3.

In another class of preferred embodiments, the pair of primers specific for amplification of feline-derived components is selected from the group consisting of:

primer 1: 5'-agcacgaaag taactttaac acctcc-3', SEQ ID NO: 1;

primer 2: 5'-tgctagtagt tctctggcgg atag-3', SEQ ID NO: 2.

in another preferred class, the feline-derived component-specific probe is a Taqman probe (particularly a Taqman MGB probe).

In another class of preferred embodiments, the probe sequences are as follows:

5’-actacacgac agctaaga-MGB-3’，SEQID NO：3。

in another class of preferred embodiments, the method further comprises the steps of: detecting the fluorescent signal emitted by the feline-derived component-specific probe during or after the polymerase chain reaction.

In a second aspect of the present invention, there is provided a test kit comprising the following reagents:

(a) and amplifying a cat-derived component by using a specific primer pair, wherein an amplification product amplified by using the primer pair has a nucleotide sequence shown as SEQ ID NO: 5, the nucleotide sequence of the cat mitochondrial 12S rRNA gene; and

(b) a feline-derived component-specific probe, and the feline-derived component-specific probe binds to a peptide set forth in SEQ ID NO: 5, the nucleotide sequence of the cat mitochondrial 12S rRNA gene.

primer 1: 5'-agcacgaaag taactttaac acctcc-3', SEQ ID NO: 1

Primer 2: 5'-tgctagtagt tctctggcgg atag-3', SEQ ID NO: 2.

in another preferred class, the feline-derived component-specific probe is a Taqman MGB probe.

In a third aspect of the present invention, there is provided a method for detecting whether a sample to be detected contains a feline-derived component, comprising the steps of:

(a) extracting nucleic acid components from a sample to be detected;

(b) and carrying out polymerase chain reaction on the extracted nucleic acid components in a polymerase reaction system, wherein the reaction system contains a specific primer pair for amplifying the cat-derived component and a cat-derived component specific probe, and an amplification product amplified by the primers has a nucleotide sequence shown in SEQ ID NO: 5, and the cat-derived component specific probe is combined with a nucleotide sequence of a cat mitochondrial 12S rRNA gene shown as SEQ ID NO: 5, the nucleotide sequence of the cat mitochondrial 12S rRNA gene;

wherein, if a nucleic acid corresponding to the amino acid sequence as set forth in SEQ ID NO: 5, the amplification product of the nucleotide sequence of the cat mitochondrial 12S rRNA gene indicates that the sample to be detected contains cat-derived components.

In another class of preferred embodiments, the nucleic acid sequence corresponding to the amino acid sequence as set forth in SEQ ID NO: 5, the amplification product of the nucleotide sequence of the cat mitochondrial 12S rRNA gene indicates that the sample to be detected does not contain cat-derived components, or the content of the cat-derived components is lower than the lower limit of the detection sensitivity (e.g., 0.0001%).

In another preferred class, the polymerase chain reaction is fluorescent real-time PCR.

In another class of preferred embodiments, the pair of primers specific for amplification of a feline-derived component is selected from the group consisting of:

primer 1: 5'-agcacgaaag taactttaac acctcc-3', SEQ ID NO: 1

Primer 2: 5'-tgctagtagt tctctggcgg atag-3', SEQ ID NO: 2.

in another preferred class, the sample to be tested is a food or feed.

In a fourth aspect of the invention, there is provided a polypeptide having a sequence as set forth in SEQ ID NO: 5 or a primer pair capable of specifically amplifying the nucleic acid molecule, and is used for preparing a kit for detecting cat-derived ingredients.

In another class of preferred embodiments, the primer pair is selected from the group consisting of:

primer 1: 5'-agcacgaaag taactttaac acctcc-3', SEQ ID NO: 1

Primer 2: 5'-tgctagtagt tctctggcgg atag-3', SEQ ID NO: 2.

in another preferred class, the kit further comprises a nucleic acid sequence shown in SEQ ID NO: 3, and (b) a probe shown in (3).

It is to be understood that within the scope of the present invention, the above-described technical features of the present invention and the technical features specifically described below (e.g., examples) may be combined with each other to constitute a new or preferred technical solution. Not to be reiterated herein, but to the extent of space.

Drawings

FIG. 1 shows the feline 12S rRNA gene and the nucleic acid sequences upstream and downstream thereof (SEQ ID NO: 4) as well as the sequences of specific primers and probes.

FIG. 2 shows a real-time fluorescence PCR detection profile using specificity of cat-derived primer probes in one embodiment of the invention.

FIG. 3 shows a graph of the sensitivity of real-time fluorescent PCR detection using cat-derived primer probes in an embodiment of the invention. Wherein,

a: detecting specificity, and amplifying cat DNA; b: and (3) detecting the sensitivity, wherein the amplification curves from left to right are respectively: 10% cat DNA, 1% cat DNA, 0.1% cat DNA, 0.01% cat DNA, 0.001% cat DNA, 0.0001% cat DNA.

FIG. 4 shows a linear relationship between Ct value and template amount.

FIG. 5 shows a spectrum of real-time fluorescent PCR detection of cat-derived components for meat products in an embodiment of the present invention.

FIG. 6 shows a graph of real-time fluorescent PCR detection of feline-derived components in a plant feed in an embodiment of the present invention.

Detailed Description

The present inventors have conducted extensive and intensive studies on various gene sequences of cat-derived ingredients, and have considered that the nucleotide sequences shown in SEQ ID NO: 5 is particularly suitable for detecting and identifying cat-derived components. Aiming at the region, not only primers for amplifying cat-derived components with extremely high specificity can be designed, but also cat-derived component probes with extremely high specificity can be designed. Thus, cat-derived components can be identified quickly and easily by detecting the fluorescent signal of TaqMan MGB probe in one PCR reaction.

As used herein, the term "feline-derived component-specific probe" refers to a primer (pair) that amplifies an amplification product having the sequence as set forth in SEQ ID NO: 5, the nucleotide sequence of the cat mitochondrial 12S rRNA gene. A preferred primer pair has the sequence of SEQ ID NO: 1 and 2.

As used herein, the term "feline-derived component-specific probe" refers to a probe that is capable of binding to an amplification product of a feline-derived component, but not to amplification products of other species (e.g., swine, cattle, sheep, etc.). More preferably, the cat-derived component specific probe specifically binds to a cat-derived component as shown in SEQ ID NO: 5, the nucleotide sequence of the cat mitochondrial 12S rRNA gene. One preferred probe has the sequence of SEQ id no: 3, and (b) is the sequence shown in the specification.

Real-time fluorescence PCR is a closed amplification detection method, amplification and detection can be carried out after an amplification system finishes sample adding, and analysis is carried out after amplification is not needed; not only reduces the possibility of environmental pollution, but also has higher specificity than common PCR because of the co-hybridization of the primer pair and the probe.

The TaqMan polymerase chain reaction technology utilizes Taq enzyme 5 '→ 3' exonuclease activity to cut off a hybridization probe in the extension process and eliminate the quenching effect of a fluorescent group at the 3 'end of the probe on a signal of a marker reporter fluorescent group at the 5' end. The intensity of the fluorescence signal is in direct proportion to the quantity of the PCR products, and the detection system can predict the quantity of the PCR products by detecting fluorescence.

Preferred amplification regions in the methods of the invention are those of feline-derived components, such as SEQ ID NO: 5 (corresponding to the 374-507 sequence in SEQ ID NO: 4), which is specific to the feline-derived component, can be used for detecting the feline-derived component.

In light of the teachings of the present invention, one skilled in the art will be able to design and synthesize primers and cat-derived component specific probes and use them in fluorescent real-time PCR qualitative and quantitative detection techniques.

In the present invention, the conditions for the steps such as total extraction of DNA from a sample, PCR amplification, and fluorescence detection are the same as those in the prior art except that the target sequence to be detected is different from those in the prior art, and it is well within the ordinary skill of the art to perform the above-mentioned various steps using conventional conditions.

In a preferred embodiment of the invention, the electrophoresis results show that primers specific for amplification of feline-derived components can amplify nucleic acids of feline-derived components. The real-time fluorescence detection result shows that the kit only shows positive performance in the sample containing the cat-derived component, and the expected effect is achieved. This indicates that the cat-derived component specific probes selected by the rational selection are extremely efficient and specific.

When real-time fluorescence detection is performed by using a quantitative PCR instrument, detection can be performed at wavelengths of 530nm or 640nm and the like according to the difference of fluorescent markers (FAM, TET).

The main advantages of the invention are:

(1) can simply, conveniently and quickly detect and identify the cat-derived ingredients.

(2) Based on the nucleotide sequence as shown in SEQ ID NO: 5 can effectively and specifically amplify the nucleic acid sequence of the cat-derived component, and the cat-derived component specific probe can more specifically distinguish the cat-derived component.

(3) The detection result has good linearity and can be used for quantitative analysis.

(4) The real-time fluorescence PCR amplification process can detect the amplification product without an electrophoresis detection process, thereby shortening the detection time and being safe to the environment and personnel because no ethidium bromide carcinogen is adopted. In addition, the detection result can be directly confirmed because the specific probe is added.

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Experimental procedures without specific conditions noted in the following examples, generally followed by conventional conditions, such as Sambrook et al, molecular cloning: the conditions described in the Laboratory Manual (New York: Cold Spring Harbor Laboratory Press, 1989), or according to the manufacturer's recommendations.

Example 1

Experimental materials and methods

1.1 materials

Animal species: 29 animals, such as cat meat, cat blood, dog meat, beef, pork, goat meat, sheep meat, sika deer meat, camel meat, horse meat, donkey meat, rabbit meat, wild pork, racoon dog meat, chicken, duck meat, goose meat, turkey, pigeon, quail, snake meat, bullfrog, frog meat, grass shrimp, crab, grass carp, oyster, mussel, snail and the like, are purchased from Shanghai markets.

Plant species: soybean, corn, barley, wheat, rice, potato, tomato, pea, cotton, rape and other 10 kinds of common plant material.

1.2 reagents

(1) Primer and TaqMan MGB fluorescent probe sequence:

12Scat-1：5’-AGCACGAAAGTAACTTTAACACCTCC-3’(SEQ ID NO：1)

12Scat-2：5’-TGCTAGTAGTTCTCTGGCGGATAG-3’(SEQ ID NO：2)

12Scat-P：5’-ACTACACGACAGCTAAGA-MGB-3’(SEQ ID NO：3)

(2) liquid nitrogen;

(3)

magnetic DNA Purification system for Food, Magnetic bead method DNA extraction kit, Promega corporation CAT. # FF 3750;

(4)

genomic DNA Purification Kit, DNA extraction Kit, Promega corporation CAT. # A1250;

(5) isopropyl alcohol;

(6) 70% ethanol;

(7) TE buffer, pH8.0

(8)ABI TaqMan Universal PCR Master Mix(Part Number 4304437)

(9) Ultrapure water (ddH)₂O)。

1.3 instrumentation

(1) ABI 7300 real-time fluorescence PCR instrument

(2) Balance with a movable handle

(3) Liquid-transfering gun

(4) Centrifugal machine

(5) Constant temperature incubator

(6) Freezing mill

(7) DNA freeze drying centrifuge

(8) Nucleic acid protein concentration analyzer

(9) Eppendorf centrifuging tube

(10) PCR reaction tube

1.4 preparation of samples

1.4.1 grinding of samples

The meat samples were ground to a powder using a freeze grinder (SPEX 6850).

1.4.2 sample preparation

Mutton and wheat were ground into powder using a refrigerated grinder and dried at 120 ℃ for 6 hours. Mutton powder and wheat flour are respectively used for preparing mixed samples with the content of the cat meat powder of 0.01 percent (W/W).

1.5 extraction of DNA

According to

The DNA extraction kit for Magnetic DNA Purification system for Food (Promega corporation CAT. # FF3750) extracts the above sample DNA. By using

Genomic DNAPuration Kit (Promega corporation CAT. # A1250) DNA extraction Kit extracts CAT blood DNA.

1.6DNA concentration determination and preparation

The concentration of the extracted sample DNA was determined using a nucleic acid protein analyzer of the Eppendorf Biophorometer type, Germany.

The extracted cat blood DNA solution (concentration: 100 ng/. mu.L) was diluted with wheat DNA solution (concentration: 100 ng/. mu.L) to a mixed solution of 10 ng/. mu.L, 1 ng/. mu.L, 0.1 ng/. mu.L, 0.01 ng/. mu.L, 0.001 ng/. mu.L, 0.0001 ng/. mu.L, and 0.00001 ng/. mu.L, which contained 10%, 1%, 0.1%, 0.01%, 0.001%, 0.0001%, and 0.00001% of the relative DNA content.

1.7PCR assay

1.7.1PCR reaction System

The reaction system for real-time fluorescent PCR detection is shown in Table 1.

TABLE 1 reaction System for real-time fluorescent PCR detection

1.7.3PCR reaction cycling parameters

Real-time fluorescent PCR reaction cycle parameters: at 50 ℃ for 2 min; at 95 ℃ for 10 min; circulating for 40 times at 95 deg.C for 15s and 60 deg.C for 1 min.

1.8 sensitivity test

LOD is the lowest sample concentration that can be detected with a probability of detection of more than 95%. LOD can be determined by establishing a series of samples at different concentrations and performing a sufficient number of repeated tests, or by repeatedly testing a series of reference materials for different amounts of the gene template of interest.

The expression of LOD may be the copy number of the DNA molecule, the relative percentage of the DNA molecule, or the mass of the DNA. The experiment is expressed in terms of the relative percentage of DNA molecules and the mass of DNA as a sensitivity test.

2 results and analysis

2.1 design of primer probes for endogenous genes in cats

According to 12S rRNA gene and nucleotide sequence (936bp-1895bp) at the upper and lower streams of the gene in cat mitochondrial genome (GenBank numbering: U20753) (shown as SEQ ID NO: 4), the design of the primer fully considers the factors such as the consistency of the annealing temperature of the detection primer and the probe of the cat 12S rRNA gene and the similarity of GC content, the primers and the probe for detecting cat-derived components are designed by adopting DNMAN 8.0 software, and the nucleotide sequence and the primer probe sequence at the upper and lower streams of the cat 12S rRNA gene are shown in figure 1. The homology of the primer probe is searched through the Blast function of GenBank, the gene has high specificity, and the homology of other genes and the gene is very small.

Primers and probes

12Scat-1：5’-AGCACGAAAGTAACTTTAACACCTCC-3’(SEQ ID NO：1)

12Scat-2：5’-TGCTAGTAGTTCTCTGGCGGATAG-3’(SEQ ID NO：2)

12Scat-P：5’-ACTACACGACAGCTAAGA-MGB-3’(SEQ ID NO：3)

The sequence of the PCR product obtained by the amplification of the primer pair (SEQ ID NO: 1 and 2) is shown as SEQ ID NO: 5, corresponding to SEQ ID NO: 374 and 507 in 4.

2.2 Cat-derived component real-time fluorescence PCR species specificity detection results

The results of the detection of cat DNA and other test animal and plant sample DNA using cat-derived detection primers are shown in fig. 2, where amplification occurred only in cat DNA (fig. 2).

2.3 real-time fluorescence PCR sensitivity detection results of Cat-derived ingredients

The assay was performed on 100 ng/. mu.L (100%), 10 ng/. mu.L (10%), 1 ng/. mu.L (1%), 0.1 ng/. mu.L (0.1%), 0.01 ng/. mu.L (0.01%), 0.001 ng/. mu.L (0.001%), 0.0001 ng/. mu.L (0.0001%), 0.00001 ng/. mu.L (0.00001%) of cat DNA.

The results are shown in FIG. 3. In fig. 3, a: detecting specificity, and amplifying cat DNA; b: and (3) detecting the sensitivity, wherein the amplification curves from left to right are respectively: 10 ng/. mu.L (10%) cat DNA, 1 ng/. mu.L (1%) cat DNA, 0.1 ng/. mu.L (0.1%) cat DNA, 0.01n g/. mu.L (0.01%) cat DNA, 0.001 ng/. mu.L (0.001%) cat DNA, 0.0001 ng/. mu.L (0.0001%) cat DNA.

Amplification occurred in all cat DNA at > 0.0001 ng/. mu.L (0.0001%) (FIG. 3). This indicates that the cat-derived detection primer is species-specific and the detection sensitivity is 0.0001 ng/. mu.L (0.0001%) of cat DNA. Taking logarithm (x) of DNA template quantity and Ct value (y) as standard curveAnd obtaining a linear regression equation (figure 4); the linear relationship between Ct value and template quantity is good, R²Is 0.9976. The results show that the method can carry out quantitative analysis on the DNA concentration (relative content) of the cat.

2.4 detection of Cat-derived ingredients in meat products (animal products)

The detection research of cat-derived ingredients in animal raw material products is carried out by adding cat meat ingredient positive substances. The cat meat powder sample is added into a mutton powder matrix which takes animals without cat ingredients as raw materials to prepare a 0.01 percent added sample. The method is applied to detection to simulate the detection of cat-derived ingredients in animal products.

The experimental result shows that the PCR negative control result has no amplification curve, the reaction result is normal, and the reaction system has no pollution. The results of detecting the cat-derived components in the animal raw material products show that the method can detect 0.01 percent of cat-derived component substances in the animal raw material products (figure 5).

2.5 detection of Cat-derived ingredients in vegetable feeds (plant products)

The cat meat positive substances are added to perform detection research on cat-derived ingredients in plant raw material products. The cat meat powder sample was added to a wheat flour base made of a plant containing no cat component to prepare a 0.01% added sample. The method is applied to detection to simulate the detection of cat-derived ingredients in plant products.

The experimental result shows that the PCR negative control result has no amplification curve, the reaction result is normal, and the reaction system has no pollution. The results of detecting the cat-derived components in the plant raw material products show that the method can detect 0.01 percent of cat-derived component substances in the plant raw material products (figure 6).

3 conclusion

The real-time fluorescent PCR detection primer probe which is developed by the invention and aims at detecting the 12S rRNA gene of the cat is suitable for detecting the cat-derived components in raw materials (cat meat) and processed products (food, feed and the like), and can be applied to daily inspection and quarantine work.

Example 2

Detection of food and feed

Primers (SEQ ID NOS: 1 and 2) were used to bind to the amino acid sequence of SEQ ID NO: and 3, respectively carrying out real-time fluorescence RT-PCR detection on cat-derived ingredients by the probe through real-time fluorescence RT-PCR on 15 batches of food and feed samples purchased from the market, and detecting the cat-derived ingredients from 4 batches of food.

In addition, the nucleotide sequence of the amplification product of the detected sample is determined by a sequencer, and the result shows that the amplified cat-derived component is shown as SEQ ID NO: 5, the nucleotide sequence region of the feline mitochondrial 12S rRNA gene.

TABLE 2 fluorescent real-time RT-PCR assay results for different batches of samples

Batches of	Sample name	Source ground	The result of the detection
				1	Cat meat	Shanghai province	Positive for
2	Kebab	Shanghai province	Positive for
				3	Unknown meat block	Guangzhou restaurant with certain wild flavor	Positive for
4	Meat block	Another wild store of Guangzhou	Positive for
				5	Meat block	Shanghai restaurant	Negative of
6	Meat block	Shanghai restaurant	Negative of
				7	Spiced meat block	Shanghai restaurant	Negative of
8	Meat and bone meal	Australia	Negative of
				9	Fish meal	Peru (Peru)	Negative of
10	Fish meal	United states of America	Negative of
				11	Feed additive	United states of America	Negative of
12	Feed stuff	Shanghai province	Negative of
				13	Feed stuff	Jiangsu	Negative of
14	Feed stuff	Guangzhou province	Negative of
				15	Feed stuff	Guangzhou province	Negative of

All documents referred to herein are incorporated by reference into this application as if each were individually incorporated by reference. Furthermore, it should be understood that various changes and modifications of the present invention can be made by those skilled in the art after reading the above teachings of the present invention, and these equivalents also fall within the scope of the present invention as defined by the appended claims.

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Claims

1. A method of polymerase chain reaction comprising the steps of:

performing polymerase chain reaction in a polymerase reaction system, wherein the reaction system contains a specific primer pair for amplifying the cat-derived component and a cat-derived component specific probe, and an amplification product amplified by the primer is a nucleotide sequence shown as SEQ ID NO: 5 of a nucleotide sequence of a cat mitochondrial 12S rRNA gene,

wherein the nucleotide sequence of the cat-derived component specific probe is shown as SEQ ID NO: 3, the specific primer pair for amplifying the cat-derived component is as follows:

primer 1: 5'-agcacgaaag taactttaac acctcc-3', SEQ ID NO: 1 and

primer 2: 5'-tgctagtagt tctctggcgg atag-3', SEQ ID NO: 2.

2. the method of claim 1, wherein said feline-derived component-specific probe is a Taqman MGB probe.

3. The method of claim 2, wherein the method further comprises the steps of: detecting the fluorescent signal emitted by the feline-derived component-specific probe during or after the polymerase chain reaction.

4. A test kit, comprising the following reagents:

(a) a specific primer pair for amplifying cat-derived components, wherein an amplification product amplified by the primer pair is a primer set shown as SEQ ID NO: 5, the nucleotide sequence of the cat mitochondrial 12S rRNA gene; and

(b) the cat-derived component specific probe, and the nucleotide sequence of the cat-derived component specific probe is shown as SEQ ID NO: 3 is shown in the specification; the specific primer pair for amplifying the cat-derived component is as follows:

primer 1: 5'-agcacgaaag taactttaac acctcc-3', SEQ ID NO: 1 and

primer 2: 5'-tgctagtagt tctctggcgg atag-3', SEQ ID NO: 2.

5. the kit of claim 4, wherein the cat-derived component specific probe is a Taqman MGB probe.

6. A method for detecting whether a sample to be detected contains a cat-derived component is characterized by comprising the following steps:

(a) extracting nucleic acid components from a sample to be detected;

(b) and carrying out polymerase chain reaction on the extracted nucleic acid components in a polymerase reaction system, wherein the reaction system contains a specific primer pair for amplifying the cat-derived component and a cat-derived component specific probe, and an amplification product amplified by the primers is shown as SEQ ID NO: 5, and the nucleotide sequence of the cat mitochondrial 12S rRNA gene is shown as SEQ ID NO: 3 is shown in the specification;

wherein, if a nucleic acid corresponding to the amino acid sequence as set forth in SEQ ID NO: 5, the amplification product of the nucleotide sequence of the cat mitochondrial 12S rRNA gene indicates that the sample to be detected contains cat-derived components;

wherein the specific primer pair for amplifying the cat-derived component is as follows:

primer 1: 5'-agcacgaaag taactttaac acctcc-3', SEQ ID NO: 1 and

primer 2: 5'-tgctagtagt tctctggcgg atag-3', SEQ ID NO: 2.

7. a polypeptide with a sequence shown as SEQ ID NO: 5 or a primer pair of SEQ ID NO: 1 and SEQ ID NO: 2, and is characterized by being used for preparing a kit for detecting cat-derived components.