Frequently Asked Questions
Billing
What is the fee per strain of duckweed?
Starting from Jan 1, 2024, $110.00 per strain for academic institutions, and $165.00 per strain for non-academic use (e.g. commercial, government laboratories or personal use). The requester is also responsible for all shipping charges.
Starting from Jan 1, 2024, $110.00 per strain for academic institutions, and $165.00 per strain for non-academic use (e.g. commercial, government laboratories or personal use). The requester is also responsible for all shipping charges.
What forms of payment are accepted?
Only checks and money orders are accepted. We no longer accept personal checks; individuals not affiliated with an institution or company should submit a money order or cashier's check. Payment must be received to process your order (i.e. to prepare the requested strains).
Only checks and money orders are accepted. We no longer accept personal checks; individuals not affiliated with an institution or company should submit a money order or cashier's check. Payment must be received to process your order (i.e. to prepare the requested strains).
My institution/company requires a W-9 to process the invoice. How can I obtain this form?
Please contact the RDSC Manager to receive a copy of Rutgers University's W-9 form.
Please contact the RDSC Manager to receive a copy of Rutgers University's W-9 form.
Shipping
How are orders shipped?
All orders are shipped via FedEx overnight shipping. Shipping charges (typically $10-20 per order) will be calculated after you submit the order form and will be included on the emailed invoice. You may also pick up your order at the RDSC.
All orders are shipped via FedEx overnight shipping. Shipping charges (typically $10-20 per order) will be calculated after you submit the order form and will be included on the emailed invoice. You may also pick up your order at the RDSC.
Where can orders be shipped?
We only ship to addresses within the United States. Laws and regulations for importing live plants vary from country to country, often requiring phytosanitary certification. At this time, we lack the administrative capacity to deal with these regulations.
As an alternative you can try contacting the following Duckweed collections:
University Of Jena, Plant Physiology
Dornburger Str. 159, 07743 Jena, Germany
Contact Person: Klaus Appenroth
Contact Email: [email protected]
Contact Phone: +49 (0)3641 949233
Chengu Institue of Biology
Chengu 610041, China
Contact Person: Hai Zhao
Contact Email: [email protected]
The full list of worldwide duckweed collections could be found from the link.
We only ship to addresses within the United States. Laws and regulations for importing live plants vary from country to country, often requiring phytosanitary certification. At this time, we lack the administrative capacity to deal with these regulations.
As an alternative you can try contacting the following Duckweed collections:
University Of Jena, Plant Physiology
Dornburger Str. 159, 07743 Jena, Germany
Contact Person: Klaus Appenroth
Contact Email: [email protected]
Contact Phone: +49 (0)3641 949233
Chengu Institue of Biology
Chengu 610041, China
Contact Person: Hai Zhao
Contact Email: [email protected]
The full list of worldwide duckweed collections could be found from the link.
How is the duckweed supplied?
Each strain is supplied in a 60 mm petri dish with 10-20 fronds. Duckweed is cultured and shipped on 0.5X SH salts + 0.5% sucrose + 0.8% agar at pH 6.0 under axenic (sterile) conditions.
Each strain is supplied in a 60 mm petri dish with 10-20 fronds. Duckweed is cultured and shipped on 0.5X SH salts + 0.5% sucrose + 0.8% agar at pH 6.0 under axenic (sterile) conditions.
Can I receive duckweed seeds?
No. Duckweed plants rarely flower and produce seeds. In fact, it is unclear what triggers flowering in many species. Thus we propagate plants vegetatively through asexual reproduction. All strains in the RDSC collection are stored as fronds.
No. Duckweed plants rarely flower and produce seeds. In fact, it is unclear what triggers flowering in many species. Thus we propagate plants vegetatively through asexual reproduction. All strains in the RDSC collection are stored as fronds.
Order Processing
How long will it take to receive my order?
Typically 2 to 3 weeks after we receive payment. The actual time will depend on the size of the order and the health of the requested clones at the time of ordering.
Typically 2 to 3 weeks after we receive payment. The actual time will depend on the size of the order and the health of the requested clones at the time of ordering.
Can orders be expedited?
Yes. Please contact the RDSC Manager if you need your order expedited. We can begin preparing your strains immediately. However, we will not ship the order until payment is received in full.
Yes. Please contact the RDSC Manager if you need your order expedited. We can begin preparing your strains immediately. However, we will not ship the order until payment is received in full.
How can I check the status of my order?
Please contact the RDSC Manager to receive an update. You will typically receive three emails during the ordering process: (1) when the invoice is generated, (2) when payment is received, and (3) when the order ships.
Please contact the RDSC Manager to receive an update. You will typically receive three emails during the ordering process: (1) when the invoice is generated, (2) when payment is received, and (3) when the order ships.
Duckweed Culture
What medium can be used for maintaining duckweed?
0.5X (1.6 g/L) Schenk and Hildebrandt (SH) Salts (Sigma Cat. # S6765; PhytoTechnology Laboratories Cat. # S816)
0.5% Sucrose (optional, stimulates rapid growth)
0.8% Agar (for solid media)
pH 6.0
0.5X (1.6 g/L) Schenk and Hildebrandt (SH) Salts (Sigma Cat. # S6765; PhytoTechnology Laboratories Cat. # S816)
0.5% Sucrose (optional, stimulates rapid growth)
0.8% Agar (for solid media)
pH 6.0
What growth conditions can be used for duckweed?
22°C, 16 hours of light and 8 hours of dark
22°C, 16 hours of light and 8 hours of dark
Is there a sterilization protocol for duckweed?
Yes. Submerge duckweed fronds in 10-20% (v/v) bleach with agitation for 30 seconds to 3 minutes, until significant whitening is evident along the edges (but the meristem is still green). Then rinse with sterile deionized water twice and transfer to fresh duckweed medium.
Yes. Submerge duckweed fronds in 10-20% (v/v) bleach with agitation for 30 seconds to 3 minutes, until significant whitening is evident along the edges (but the meristem is still green). Then rinse with sterile deionized water twice and transfer to fresh duckweed medium.
Can antibiotics be used to control bacterial contamination?
Yes. We recommend using 100 µg/mL cefotaxime.
Yes. We recommend using 100 µg/mL cefotaxime.
How can I eliminate fungal contamination?
Use the sterilization protocol above. It is imperative to act quickly because fungi can grow rapidly in the media (especially when sucrose is present) and ultimately kill the duckweed.
Use the sterilization protocol above. It is imperative to act quickly because fungi can grow rapidly in the media (especially when sucrose is present) and ultimately kill the duckweed.
Why is it difficult to keep certain duckweed strains axenic (sterile)?
Some strains appear to form strong associations with beneficial microbes. Despite aggressive sterilization procedures, bacterial contamination may persist in duckweed cultures. To minimize this contamination, you can grow plants on media that lacks sucrose or contains antibiotics.
Some strains appear to form strong associations with beneficial microbes. Despite aggressive sterilization procedures, bacterial contamination may persist in duckweed cultures. To minimize this contamination, you can grow plants on media that lacks sucrose or contains antibiotics.
How can duckweed be stored for long periods?
We typically transfer plants onto 0.5X SH medium without sucrose and store them at 15ºC under low light. Under these conditions, growth is significantly reduced and many strains can be stored for several months, or even years. Keep in mind, however, that ideal storage conditions vary, and some strains require more frequent subculturing to stave off death. Interestingly, cold can trigger the formation of dormant vegetative structures, called turions, in some strains of Spirodela polyrhiza and Lemna turionifera.
We typically transfer plants onto 0.5X SH medium without sucrose and store them at 15ºC under low light. Under these conditions, growth is significantly reduced and many strains can be stored for several months, or even years. Keep in mind, however, that ideal storage conditions vary, and some strains require more frequent subculturing to stave off death. Interestingly, cold can trigger the formation of dormant vegetative structures, called turions, in some strains of Spirodela polyrhiza and Lemna turionifera.
