Testing for Sudden Oak Death – Pathotest Immunostrip Test

We use a commerically available, EIA-based Phytophthora assay formatted for ease of use and rapid results. This method can be used in the field, with very little preparation, and the results can be available in as little as 30min. Manufacturer’s Page.
Sampling Leaves
The assay comes as a complete kit and requires no additional equipment. Sample leaves are placed in the supplied sample extraction bag. The extraction bag contains a mesh lining and the leaves are macerated by rubbing with the back of a marker pen. User’s Guide pdf
The extraction solution is already provided in the bag. The liquid in the bag will turn brown or green depending on the condition of the leaves. The sample end of the immunostrip is inserted into the channel portion of the extraction bag.
Immunostrip Assay
Immunostrip Results
The extracted leaf material automatically flows up into the immunostrip. The format is similar to home pregnancy test kits. One red line indicates a negative test and two lines indicate a positive test for Phytophthora. Positive results may be visible within 5 min but may take as long as 30min.


Pros and Cons of the Immunostrip method:
– Very use to use.
– Inexpensive compared to PCR.
– No special equipment required.
– Results available immediately.

– Faint positives may be difficult to interpret.
– Cross reacts with other Phytophthoras (false positive for SOD) and the results need to be interpreted with caution, preferably by someone with expertise in the field.

Jump to Other SOD Diagnostic Methods:
ImmunostripsCulturingEIA AnalysisPCR Analysis

The UC Berkeley Forest Pathology and Mycology Laboratory does not provide a SOD testing service. For information on SOD testing please visit www.suddenoakdeath.org

This activity possible thanks to funding from:
USDA Forest Service, State and Private Forestry
The Gordon and Betty Moore Foundation
Agdia, Inc. http://www.agdia.com

Disclaimer: Mention of any company, trade name, or commercial product does not constitute endorsement by the University of California or recommendation for use. Always follow the manufacturer’s directions, restrictions, and precautions on the product label.