Related Experiment Video
Updated: May 11, 2026
08:54
Development and Testing of Species-specific Quantitative PCR Assays for Environmental DNA Applications
Published on: November 5, 2020
Development and validation of a quantitative PCR assay for Ichthyophonus spp
Vanessa C White1, J Frank Morado, Lisa M Crosson
1National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Alaska Fisheries Science Center, Resource Assessment and Conservation Engineering Division, Seattle, Washington 98115, USA.
Diseases of Aquatic Organisms
|May 15, 2013
Summary
A new quantitative PCR (qPCR) assay effectively detects Ichthyophonus parasites in fish. This sensitive and specific method enhances parasite surveillance and can be adapted for environmental samples.
Area of Science:
- Aquatic Parasitology
- Molecular Diagnostics
- Fish Health
Background:
- Ichthyophonus are widespread fish parasites with significant ecological and economic impacts.
- Accurate detection methods are crucial for monitoring and managing Ichthyophonus infections in global fish populations.
Purpose of the Study:
- To develop and validate a quantitative PCR (qPCR) assay for detecting Ichthyophonus genus DNA.
- To compare the diagnostic performance of qPCR against conventional PCR (cPCR) and histology.
Main Methods:
- Development of a genus-specific qPCR assay targeting Ichthyophonus 18S ribosomal DNA.
- Analytical validation including precision, repeatability, reproducibility, sensitivity, and specificity.
- Diagnostic evaluation using tissue samples from wild walleye pollock (Theragra chalcogramma) compared with cPCR and histology.
Main Results:
- The developed qPCR assay demonstrated high analytical sensitivity and specificity for Ichthyophonus spp. DNA.
- qPCR identified more positive cases than cPCR or histology, particularly in walleye pollock skeletal muscle.
- qPCR offers parasite DNA quantification and a 100-fold increase in analytical sensitivity over cPCR.
Conclusions:
- The novel qPCR assay is a sensitive and specific tool for detecting Ichthyophonus parasites in fish.
- This assay can be applied to various hosts and regions for prevalence and distribution studies.
- Potential adaptations for environmental or zooplankton samples could reveal transmission routes and life history insights.
