【 JD-XC1 】 The pine wood nematode detection equipment is selected from Jingdao Technology. The field rapid inspection system can be portable and mobile for operation, automatically displaying the detection results and printing the detection report. The operation is more intelligent. It is directly sent by the manufacturer and includes teaching and training. Welcome to inquire! 】.

1、 Molecular target and probe optimization: eliminating non-specific binding from the source

The core cause of false positives is the cross reaction between primers/probes and non target sequences, which the device avoids through triple design:

High specificity target selection: Primers are designed for conserved genes such as 18S rDNA, ITS2, or COI in pine wood nematodes, and validated by NCBI BLAST to ensure no homology with closely related species such as pine wood nematodes and umbrella blade nematodes.

Double labeling probe technology: TaqMan MGB probe is used, with FAM fluorescent group labeled at the 5 'end and quenching group labeled at the 3' end. Only when the probe is complementary to the target sequence, Taq enzyme 5 'exonuclease activity hydrolyzes the probe to release fluorescence, avoiding non-specific binding interference of SYBR Green dye.

Primer concentration gradient optimization: The device has a built-in primer concentration calibration module, which recommends an optimal concentration of 0.2-0.4 μ M to reduce primer dimer formation and decrease non-specific amplification probability.

2、 Hardware pollution prevention design: blocking aerosols and cross contamination

Aerosol pollution is the main source of false positives in the field and laboratory, and equipment is protected from both structural and functional dimensions:

Partition isolation and disinfection: adopting an independent cabin design of "sample processing reagent preparation amplification detection", with a built-in UV-C disinfection module, automatically disinfecting for 3 minutes after each test to degrade residual nucleic acid; Some models are equipped with HEPA high-efficiency filters to reduce the risk of aerosol diffusion.

Adaptation of pollution prevention consumables: Comes with a filter cartridge suction head and a screw cap PCR tube to reduce aerosol emissions during sample addition; The reaction module is sealed with a hot lid and maintained at a temperature of 105 ℃ to prevent liquid evaporation and contamination.

UDG enzyme contamination prevention system: Adding DNA glycosylation enzyme (UDG) to the reagent can degrade the residual products from the previous amplification. UDG becomes inactive during pre denaturation at 95 ℃, which does not affect the reaction and fundamentally blocks product contamination.

3、 Multi quality control system: real-time monitoring of reaction reliability

The device ensures the authenticity and effectiveness of the results through multi comparison collaboration:

Negative control synchronous detection: Set template free control (NTC) and negative sample control (such as healthy pine wood) for each batch. If there is an amplification signal in the control, immediately determine that the test is invalid and investigate the source of contamination.

Internal reference gene correction: Add endogenous pine tree genes (such as 18S rRNA) primers to the reaction system to monitor the quality of sample nucleic acid extraction and amplification efficiency, and avoid false positive misjudgment caused by sample inhibitors.

Melting curve verification: When using the SYBR Green method for detection, the equipment automatically generates a melting curve. A single sharp peak indicates specific amplification, while multiple or broad peaks indicate non-specific products and require retesting.

4、 Data analysis and result judgment: precise filtering of abnormal signals

The device is optimized through algorithms to eliminate non-specific signal interference:

Ct value threshold setting: Built in AI algorithm, automatically sets fluorescence threshold, Ct ≤ 35 is positive, 35

Amplification curve quality control: The software automatically identifies effective curves with "stable baseline, obvious exponential period, and saturated plateau period", and filters out abnormal curves caused by instrument fluctuations or reagent contamination.

Result review mechanism: Positive samples require secondary testing, combined with dual target primer cross validation to ensure reliable results. At the same time, a report with timestamp and location information is generated for traceability verification.

5、 Operating standards and reagent management: building a solid human defense line for prevention and control

Operators need to operate in different zones, wear disposable gloves, regularly replace pipettes and suction tips, and clean the workbench with reagents such as DNAzap.

Reagents should be stored at low temperatures and away from light to avoid repeated freeze-thaw cycles. The effectiveness of the reagents should be regularly verified to prevent non-specific amplification caused by reagent degradation.

In summary, the fluorescence quantitative PCR pine wood nematode detection equipment comprehensively avoids false positives through the coordination of multiple links such as molecular, hardware, quality control, and operation, providing reliable technical support for precise prevention and control of pine wood nematode disease.