Analysis of the Technical Principles and Clinical Prevention and Control Applications of the Monkeypox Virus Nucleic Acid Detection Kit (Fluorescent PCR Method)

Detection Targets and Primer/Probe Design Strategy

Monkeypox virus nucleic acid detection kits (fluorescence PCR method) are typically designed with specific primers and fluorescently labeled probes targeting conserved regions of the viral genome. Common targets include the viral DNA polymerase gene, F3L or N4R fragments. During design, sequence characteristics of different monkeypox virus clades (such as the West African clade and the Congo Basin clade) must be comprehensively compared to ensure coverage of major epidemic strains while avoiding cross-reactivity with other orthopoxviruses (such as variola virus and vaccinia virus). The melting temperature, GC content, and secondary structure of primers and probes must undergo multiple optimizations to meet the efficiency and specificity requirements of fluorescence PCR amplification.

Kit Components and Key Operational Workflow Points

Conventional monkeypox virus nucleic acid detection kits (fluorescence PCR method) include nucleic acid extraction reagents, PCR reaction master mix, enzyme mix, positive control, negative control, and internal control (typically a human cellular gene, used to monitor sample quality and extraction efficiency). The operational workflow is generally divided into:

Sample collection: Commonly used specimens include throat swabs, rash exudate, or vesicle fluid, which are placed in viral transport medium after collection for transport;

Nucleic acid extraction: Magnetic bead method or column extraction method is used to obtain high-purity DNA;

Fluorescence PCR amplification: The extracted nucleic acid is added to the reaction system, and amplification and signal acquisition are performed on a real-time fluorescence PCR instrument;

Result interpretation: Based on Cq values and amplification curve morphology, combined with negative/positive control and internal control results, determine whether the sample is positive for monkeypox virus nucleic acid.

The entire process must be conducted in a laboratory meeting biosafety requirements, and operators should receive professional training.

Performance Verification and Quality Control Requirements

According to industry standards, monkeypox virus nucleic acid detection kits (fluorescence PCR method) must complete analytical performance verification before registration or filing, including:

Analytical sensitivity (limit of detection): Typically evaluated in viral copies/mL or TCID50;

Analytical specificity: Verify cross-reactivity with other orthopoxviruses, herpesviruses, and common respiratory pathogens;

Precision: Including intra-batch, inter-batch, intra-day, and inter-day reproducibility;

Interference testing: Evaluate the effects of hemolysis, lipemia, common drugs, etc., on detection.

In routine use, regular quality supervision of instruments, reagents, and personnel operations is required to ensure stable and reliable results.

Clinical Application and Public Health Prevention and Control Value

Monkeypox virus nucleic acid detection kits (fluorescence PCR method) play an important role in monkeypox epidemic prevention and control:

Early screening: Rapid testing of suspected cases with symptoms such as fever and rash to assist early diagnosis;

Confirmatory basis: Fluorescence PCR is one of the laboratory confirmation methods currently recommended by WHO and national guidelines;

Epidemiological surveillance: Testing of environmental samples from outbreak sites (such as object surfaces and medical devices) and animal hosts helps trace infection sources and transmission chains.

It should be noted that test results should be comprehensively judged in combination with epidemiological history and clinical symptoms, as any single detection method carries a probability of false negatives or false positives.