Overview of Canine Parainfluenza Virus (CPIV) Quantitative Fluorescence Detection Kit

The Canine Parainfluenza Virus (CPIV) quantitative fluorescence detection kit is a tool specifically used to detect the presence of canine parainfluenza virus in canine samples. Canine parainfluenza virus can cause respiratory diseases in dogs, such as coughing, runny nose, and fever, which are quite harmful to the health of dogs. This kit can accurately and quickly detect the virus through quantitative fluorescence PCR technology, providing an important basis for the diagnosis, treatment, and prevention of canine diseases.

II. Components of the Kit

1. Sample Processing Reagents
   • Lysis buffer: Used to break down cells in canine samples and release viral nucleic acids. The lysis buffer usually contains components such as surfactants that can rupture cell membranes.
   • Nucleic acid extraction reagents: Including alcohols (such as ethanol or isopropanol) for precipitating nucleic acids and reagents for removing impurities to ensure the extraction of relatively pure viral nucleic acids.
2. Quantitative Fluorescence PCR Reagents
   • Primers: Short – chain DNA fragments complementary to specific nucleic acid sequences of canine parainfluenza virus. They can specifically recognize and bind to viral nucleic acids to guide subsequent amplification reactions.
   • Taq DNA polymerase: This is the key enzyme for PCR reactions. It can synthesize new DNA strands using viral nucleic acids as templates under the guidance of primers.
   • Fluorescent probes: Can bind to specific nucleic acid sequences during amplification. During the PCR reaction, as new strands are synthesized, the fluorescent probes will emit fluorescence signals, and the intensity of the signals is proportional to the quantity of viral nucleic acids.
   • Reaction buffer: Provides suitable conditions such as pH value and ionic strength for PCR reactions to ensure smooth reaction.
3. Positive and Negative Controls
   • Positive control: A sample containing known canine parainfluenza virus nucleic acids, used to verify the effectiveness of the kit during the detection process. If the expected positive result is obtained from testing the positive control, it indicates that the kit and the detection process are normal.
   • Negative control: A sample without canine parainfluenza virus nucleic acids, used to detect false – positive results. If a positive result occurs in the negative control, it suggests that there may be problems such as contamination in the detection process.
4. Detection Consumables
   • PCR reaction tubes: Containers for quantitative fluorescence PCR reactions, with good thermal conductivity to ensure that reactions occur under uniform temperature conditions.
   • Pipette tips: Used to accurately aspirate and transfer liquids such as samples and reagents to prevent cross – contamination.

III. Detection Principle

1. Nucleic Acid Extraction from Samples
   • Canine samples (such as nasal swabs, throat swabs, or blood) are added to sample processing reagents. Under the action of the lysis buffer, cells in the samples are lysed, and nucleic acids are released. Then, through operations such as centrifugation, precipitation, and washing, impurities are removed, and pure viral nucleic acids are extracted.
2. Quantitative Fluorescence PCR Reaction
   • The extracted viral nucleic acids are added to PCR reaction tubes containing quantitative fluorescence PCR reagents. At the beginning of the reaction, double – stranded viral nucleic acids are first denatured into single – stranded ones at a high temperature (usually 90 – 95 °C). Then, the temperature is lowered (generally 50 – 65 °C) to enable primers to specifically bind to single – stranded viral nucleic acids (annealing). Subsequently, new – strand synthesis (extension) is carried out at a suitable temperature (usually 70 – 75 °C) under the action of Taq DNA polymerase.
   • During the extension process, fluorescent probes bind to newly synthesized DNA strands and emit fluorescence signals. As PCR cycles progress, viral nucleic acids are continuously amplified, and fluorescence signals also increase continuously. The instrument monitors the changes in fluorescence signals in real – time and quantitatively analyzes the content of canine parainfluenza virus nucleic acids in the sample according to the cycle number (Ct value) when the fluorescence signal reaches the set threshold.

IV. Sample Collection and Processing

1. Sample Collection
   • Nasal swab collection: Use a sterile swab to go deep into the dog’s nasal cavity, gently rotate the swab to collect nasal secretions. After collection, put the swab into a sampling tube containing sample preservation fluid.
   • Throat swab collection: Insert a sterile swab from the dog’s mouth into the throat, moderately wipe the throat mucosa, collect throat secretions, and then put them into a sampling tube.
   • Blood collection: Use the conventional venous puncture method to collect the dog’s blood and put it into a blood – collection tube containing an anticoagulant.
2. Sample Processing
   • Process the collected samples in the laboratory as soon as possible. Add sample processing reagents for nucleic acid extraction operations according to the kit instructions. During the processing, strictly adhere to the principle of aseptic operation to prevent sample contamination.

V. Application Scenarios

1. Clinical Diagnosis
   • In veterinary clinical practice, when a dog shows symptoms of respiratory tract infection, using this kit can quickly and accurately detect canine parainfluenza virus, helping veterinarians determine the cause and formulate a reasonable treatment plan.
2. Disease Surveillance
   • In places such as kennels, pet hospitals, and animal quarantine stations, regular virus detection can be carried out on dog populations to timely identify individuals infected with canine parainfluenza virus and take isolation, disinfection, and other prevention and control measures to prevent virus spread and diffusion.
3. Vaccine Research and Evaluation
   • During the research and development of canine parainfluenza virus vaccines, this kit can be used to detect the virus antibody levels and viral nucleic acid contents in dogs after vaccination, evaluating the immune efficacy and safety of vaccines.