Detecting Hop Latent Viroid (HLVd) in Cannabis with qPCR

Introduction to HLVd Detection

HLVd is a serious threat to Cannabis cultivation, affecting both hemp and marijuana. This viroid disrupts plant growth, leading to stunted plants, reduced cannabinoid production, and lower yields—often without immediate visible symptoms. Early and accurate detection is critical to preventing outbreaks and ensuring the health of your Cannabis plants.

Quantitative PCR (qPCR) is one of the most reliable methods for HLVd detection, offering sensitivity, specificity, and quantification in a single reaction. Our HLVd qPCR Detection Assay is specifically designed for Cannabis, providing rapid results while including an internal control to verify negative results.

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Why Use a Duplex qPCR Assay for HLVd?

qPCR is the gold standard for pathogen detection due to its ability to detect low-copy-number targets with high specificity. The duplex design of our assay allows for simultaneous detection of HLVd and an internal Cannabis control gene, ensuring confidence in negative results.

Key Advantages of Our Duplex qPCR Assay:

✔ High Sensitivity – Detects low levels of HLVd before symptoms appear.
✔ Specificity – Targets HLVd without cross-reactivity.
✔ Internal Control – Confirms successful extraction and PCR performance.
✔ Fast Results – Get results in about an hour.

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How the HLVd Duplex qPCR Assay Works

The assay uses two fluorescence channels to detect both HLVd and an internal Cannabis control:

• HLVd Detection – FAM Channel (520 nm)
• Cannabis Internal Control – HEX Channel (555 nm)

During the qPCR reaction:

1. If HLVd is present, a fluorescence signal will appear in the FAM channel.
2. The internal Cannabis gene should always amplify, generating a signal in the HEX channel.
3. If a sample is truly negative for HLVd, only the HEX channel will fluoresce, confirming that the sample is valid.
4. If no amplification is seen in either channel, it indicates a possible issue with sample extraction or reaction setup, requiring retesting.

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Interpreting qPCR Results

Sample Result	FAM (HLVd)	HEX (Cannabis Control)	Interpretation
Positive	✅ Detected	✅ Detected	HLVd Present
Negative	❌ Not Detected	✅ Detected	HLVd Absent
Invalid	❌ Not Detected	❌ Not Detected	Retest Needed

An internal control is critical for verifying negative results because it ensures that the PCR reaction worked correctly. Without it, a negative result could be due to poor sample quality rather than a true absence of HLVd.

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Best Practices for Accurate HLVd Testing

To maximize the reliability of your qPCR results, follow these best practices:

🔬 Collect High-Quality Samples – Use roots and petioles for the highest viroid concentration.
🧼 Prevent Cross-Contamination – Collect samples with clean, sterile equipment. Wear gloves and change gloves between samples. 
📏 Use Proper Controls – Always run positive and negative controls alongside test samples. We sell positive controls for HLVd.
✅ Verify Negative Results – Ensure the HEX channel amplifies to confirm a valid test.

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Why Early HLVd Detection Matters

HLVd infections can spread rapidly through cloning, contaminated tools, and worker handling. Regular testing allows cultivators to:

✔ Remove infected plants early before they spread HLVd.
✔ Protect mother plants and prevent genetic stock losses.
✔ Improve yield and cannabinoid production by maintaining viroid-free plants.
✔ Ensure compliance with industry standards for pathogen-free cultivation.

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Conclusion

Our HLVd Detection Assay provides a reliable and efficient way to detect HLVd in Cannabis. With an internal Cannabis control built into the assay, you can trust that negative results are truly negative—helping you safeguard your crop and maximize yield.

For more information on HLVd testing or to order our qPCR assay, contact us today!