Milfoil Genetic Identification Services






2013 Genetic Identifications Information

NOTES - Summer prices are still in effect.  However, due to high sample volumes and off-season personnel hours, turnaround times are longer than during the summer (up to approximately four weeks).  If you have a situation where you need the results quickly, please let Ryan know and we'll see what we can do.


Description of identification services

1) Testing for Eurasian, hybrid, and native watermilfoils

The primary purpose of this test is to determine whether a plant specimen of interest is invasive Eurasian watermilfoil (Myriophyllum spicatum; EWM), native northern watermilfoil (M. sibiricum; NWM), or a hybrid between the two (M. spicatum x M. sibiricum).

Of course, it is possible that your particular specimen turns out to be a different watermilfoil taxon altogether (e.g., M. heterophyllum, M. verticillatum, etc.).  In some cases where your specimen isn’t EWM, NWM, or hybrid, we will report the identification as “Other”.  In such cases, determination of the exact species identification may require an additional analysis and corresponding charge.  Please consult Ryan Thum.

2) Testing for variable-leaf watermilfoil

The primary purpose of this test is to determine whether a plant specimen of interest is variable leaf watermilfoil (Myriophyllum heterophyllum).  If your specimen is variable leaf watermilfoil, we will also report the specific genetic biotype, as determined in Thum et al. 2011 (Continental, Atlantic Coastal Plain, hybrid M. heterophyllum x M. laxum).  Please note that in rare cases, it is possible that your specific plant is an undescribed biotype.

3) Testing for other watermilfoils or other plant species

In general, we can provide genetic identifications for any watermilfoil specimen of interest.  In some cases, we may also be able to perform genetic identifications for other taxa.  Please inquire with Ryan Thum. 

How fast can I expect the results?  The vast majority of the time, identification turnaround times are within 1-2 weeks from receipt of the samples.  Occasionally, we have sample volumes, unusual specimens that require extensive analysis, or other circumstantial laboratory conditions that delay turnaround times.  If your results are taking unusually long, please do not hesitate to check in with Ryan Thum!  Please also note that under circumstances where genetic identifications are time-sensitive for decision making purposes, samples can be fast-tracked to guarantee a turnaround time for an additional charge.

Sample collection and shipping instructions

Please follow the instructions on the sample collection and shipping document on the website, and contact Ryan Thum with any questions.

**Please fill out the Chain of Custody form completely.  It is very important that we have a clear understanding of who is sending the plants versus who to report the results to and who to invoice. 


May 1 – August 15, 2013

The table below refers to pricing for all samples included in a single shipment (i.e., samples received at the same time).  If you intend to send samples from multiple water bodies throughout the season, inquire with Ryan Thum for pricing.  Similarly, for individual lake projects with detailed genetic sampling (e.g., >20 in a single lake), inquire with Ryan Thum about pricing options to meet your specific needs.

Fast track – standard turnaround times are less than 10 business days.  However, if you need guaranteed fast turnaround, we can guarantee three business days or less for an additional charge of $100 (covers up to 20 processed plants; for >20 plants, please inquire with Ryan Thum).

Poor samples – Plants that arrive in poor condition may be subject to the set up charge of $65.  Please see sample collection and shipping instructions, or call Ryan Thum, to determine how to avoid plants arriving in poor condition. 

In general, we have found that plants received in the Fall (after the growing season has ended) are more likely to yield poor quality DNA for genetic analysis.  In these cases, turnaround times may be longer than 10 business days due to additional processing requirements for poor quality DNA samples.  

August 15 – December 20 – The above prices and turnaround times are subject to change due to seasonal changes in lab staffing.  We will update these prices as the end of the summer nears.  Please inquire with any questions.


1.      Chain of Custody Record  [download form]

2.      Collection and Shipping Protocol [download form]


If you have any questions, please feel free to contact:

Ryan Thum

616-331-3989 (office); 616-331-3990 (lab)


Page last modified September 28, 2013