CGC FAQ (version June 2019)

  • I have never worked with C. elegans -- where do I start?
  • If you are new to worms, here are a couple links to some introductory materials that you might find helpful:

    http://www.wormbook.org/chapters/www_celegansintro/celegansintro.html
    http://www.wormbook.org/chapters/www_strainmaintain/strainmaintain.html

    There is a lot of great information freely available on WormBook.org and WormBase.org

  • Will I receive a stock of E. coli with my worm strains?
  • Separate plates of bacteria to use a food source for your worms are not included with worm strains. However, OP50 and several other strains of bacteria can be ordered through our website. Bacteria are sent on agar plates. You should not need to order OP50 ahead of time; if you order OP50 with your strains, the worms will be fine for a few days until you have grown up the OP50 culture and prepared plates. We do not provide NGM plates or other consumables.
  • How do I place an order for worm or bacterial strains?
  • Orders must be placed through our website (https://cgc.umn.edu/). You must have a lab code before you can place an order through our site. You should receive a confirmation email for your order, and a second confirmation if using a credit card. Let us know if you do not receive the order confirmation within 24 hours to confirm your order was received in our system.
  • How do I receive a lab code?
  • If your lab does not yet have a code, please go to https://cgc.umn.edu/laboratory/request. We are required to have an institutional billing address when setting up your customer account. Codes are assigned to the PI of the lab/research group, so if you are not the PI, provide their name in the PI or lab head field. Only Laboratory Heads (PIs) may receive a lab code. Once assigned, a PI’s lab code will stay with them if they move their lab to a new institution; please notify us of any changes so that we can update your account information. Lab codes are not transferred to post-docs or other members of the lab if they leave to start their own research group.

    If your lab has previously ordered from the CGC, set up your user account by going to https://cgc.umn.edu/register and following the instructions there to set up the Admin/PI user account. Search for your lab’s code or the last name (family name) of the PI/lab head in the lab affiliation field, and select your lab code from the pull-down menu so that it populates the field. (If you see both an alphabetic lab code and a numeric lab code with your PI’s name, be sure to select the alphabetic code! Do not use the old numeric code)

    The PI’s name should be listed as the PI/lab head; however, someone else may use their email address to set up the admin user account. Be sure to select the admin/PI option when setting up the account; that account will have admin privileges for the lab, including restricting individual users accounts affiliated with the lab code (i.e. - each person orders their own strains rather than one individual placing all the orders), setting billing addresses, etc. Correspondence will be sent to the email address used to set up the account. If someone else does the ordering for the lab, we recommend that PI set up the lab's admin/PI account, activate that main account once receiving the confirmation email, and then have other users set up their individual lab member user accounts to use when ordering strains. Alternatively, some labs have created a shared Gmail account, for example, to use as a shared log-in.

  • How do I receive alphabetic code (designations) for naming new strains and alleles?
  • At this time the CGC can only assign numeric codes that may be used to order through our site. If you require alphabetic designations for naming new strains and alleles generated in your lab, you should contact Dr. Tim Schedl (genenames@wormbase.org). Once your lab receives alphabetic designations, please notify us so that we can update your account to use your alphabetic code.
  • How do I know if my lab already has a code?
  • Go to https://cgc.umn.edu/register and search for the last name (family name) of the PI/lab head in the lab affiliation field, and you should be able to select your lab code from the pull-down menu if the lab has been registered with the CGC. If you cannot find a lab code associated with your PI’s name, the lab is likely not yet set up in our system. If you think your lab has ordered before, but you cannot find your PI listed in our system, please contact us at cgc@umn.edu for more information.
  • How much does it cost to order worms or bacteria?
  • In 2007, the National Institutes of Health (NIH) mandated that we initiate a cost-recovery program to partially fund our program. The funds generated by these fees partially offset the expenses associated with maintaining the CGC operation and shipping costs.

    Each laboratory or company will be charged an annual account fee of $30. In addition, all users shall pay a flat fee per strain. In the case of academic/non-profit organizations, a $10.00 fee per strain (worms or bacteria) shall be paid by the recipient. For commercial organizations, a $150.00 fee per strain shall be paid by the recipient. We do have some strains that cannot be sent to commercial labs -- it is clearly noted in that strain's description if that is the case for a given strain.

    To partially offset the higher costs of sending strains internationally, a small processing charge will be added to each international order:


    1-7 strains: $3
    8-15 Strains: $5
    16 strains or more: $8

  • What if I only want to place a single order…do I still have to pay $30 annual fee?
  • The annual fee is essentially a one-year subscription for our service. The fee is automatically added to the first order placed once it becomes due, and covers that lab for one year from the time of that order. We will not bill you for the fee again until the lab places another order after that year of coverage has lapsed.
  • How do I know if my $30 annual fee is due?
  • The date your lab’s annual fee will be due appears near the top of the page when logged into the system.
  • How much does shipping cost?
  • Strains will be shipped by regular first class post (United States Postal Service) at no additional cost to you. We will ship via FedEx or DHL upon request, but only if you provide a FedEx or DHL number for us to use when setting up the shipment. We cannot use our FedEx account and bill you for our costs. If you would like your order shipped using FedEx or DHL, you must specify which courier (FedEx or DHL) and provide your 9-digit FedEx or DHL account number in the “Order Notes” section when placing your order. (Your DHL number should begin with 95- or 96- as DHL uses different numbers for import and export for each account.) NOTE: if you request shipping via FedEx or other courier, you will be responsible for any charges incurred for the shipment. The FedEx shipping process does not end if you choose to simply not claim the package or go through customs clearance: the default is that the package is returned to the sender at their expense if arrangements are not made to prevent that. This can amount to hundreds of dollars with the added taxes and fees charged to us for the initial shipment plus the return shipment. You are still responsible for any charges we incur for this shipment, even if you do not clear the package.

    We will only use couriers such as FedEx or DHL when shipping to the UK or Spain under special circumstances due to recurring problems with customs. Packages will be denied entry, returned to us (often at our expense), or detained for prolonged periods pending approval of import permits.
  • I want to order more than one plate of each strain. How do I add them to my cart?
  • We do not allow users to specify quantities when placing orders. As a stock center, we provide the requested strains, and it is up to the recipient to expand and maintain populations as needed for their work. The stocks will arrive starved and should be transferred to new plates before working with them anyway, so it is trivial to expand populations at that time.
  • How long will it take to get my worms?
  • Most orders take 1-2 weeks to prepare and we allow at least 4 weeks for international shipments due to possible delays in customs, etc. New strain requests are processed daily: requested strains are prepared from stocks actively growing in the lab for other orders, thawed from frozen stocks, or recovered from a starved plate kept in an incubator at 11°C. Animals are placed on freshly prepared Nematode Growth Medium (NGM) petri plates with a lawn of E. coli OP50 as a food source, and allowed to reproduce for several days. The visible phenotype of each stock is observed to confirm that it matches its description. The petri plates are then wrapped with Parafilm® and mailed to the requester. It typically takes 7-10 days for ordered strains to be prepared for shipping. Some strains such as those with temperature-sensitive phenotypes and strains with complex genotypes will often take longer to prepare for shipping.
  • How can I tell if my order has been sent?
  • You may view the status of your order in your order history to see if it is still being processed. Orders are marked as “Completed” when an order has shipped.
  • How are strains shipped?
  • Strains are sent on small agar plates packed in a padded envelope/mailing bag. If using a courier such as FedEx, the padded envelope is typically placed inside the courier’s standard cardboard envelope. Plates contain a mixed-stage population of worms, and are typically starved to make them more tolerant of environmental stresses during shipping. We do not send frozen stocks. We will not pack strains in foam boxes, include ice packs, etc. If your order will be sent to an extremely hot climate, please contact us before placing your order to discuss options or special arrangements.
  • I am outside the US…will my strains get through customs?
  • International shipments (to addresses outside the USA) will have a customs form applied to the package describing the contents as "Non-hazardous biological specimens for lab research use only, non-parasitic, non-pathogenic, non-infectious” and declaring the full value of the order. If specific permits or other documents are required for import into the receiving country, the requester should supply the CGC with the necessary forms and instructions when submitting their order.

    We will not provide false descriptions of the contents or undervalue the order to bypass customs or taxation. We will not split large orders into smaller packages of 1-2 strains to avoid customs – if you want your strains shipped in packages containing only two strains, please order two strains at a time and request in the comments on each order that they should not be combined for shipping.
  • In what condition will my strains arrive?
  • Strains are sent alive on NGM petri plates with the worms starved or still feeding on E. coli OP50. Starvation in worms does not have the same connotation as it might in other organisms. Worms are tough and can survive without food for extended periods of time. They do this in part by forming "dauer" larvae, which are dark and thin and often lie motionless.

    Strains are sent with a Strain Information Sheet, which gives the genotype, phenotype, culturing conditions and derivation of the stock, as well as a bibliographic reference. The CGC should be acknowledged in any publication that results from the use of strains acquired from the CGC.
  • What should I do with my strains when they arrive?
  • Worms should be transferred to new plates of fresh media seeded with OP50 as soon as possible after arrival. If there are enough live animals crawling on the surface, you can move individuals. Otherwise, cut a ~1cm x 1cm chunk of agar and transfer it to a new plate with a flame-sterilized scalpel or spatula. There are often starved animals that have burrowed into the agar that will crawl out when moved to a plate with food. Check the animals for the correct phenotypes, freeze them, use them for excellent experiments, and acknowledge the CGC in all publications resulting from use of the strains). If you are new to worms, here are a couple links to some introductory materials that you might find helpful:

    http://www.wormbook.org/chapters/www_celegansintro/celegansintro.html
    http://www.wormbook.org/chapters/www_strainmaintain/strainmaintain.html

    We encourage users with access to -80⁰C or liquid nitrogen freezers to make frozen stocks of strains received from us.
  • Why can’t I specify a quantity of strains?
  • We do not allow users to specify quantities when placing orders. As a stock center, we provide the necessary strains and it's up to the recipient to expand and maintain populations as needed for their work. The stocks will arrive starved and should be transferred to new plates before working with them anyway, so it is trivial to expand populations at that time.
  • Are there other shipping methods I can use?
  • To reduce the likelihood that your worms will die during transit, the CGC recommends you use overnight couriers during periods of extreme weather when low temperatures are anticipated to be near 0⁰F or high temperatures are above 85⁰F. We also recommend using an overnight courier if your order is more than ~25 strains, you have had problems receiving shipments in the past, or the requested strains are needed as soon as possible for your work so that you can receive more detailed tracking information about your shipment.

    We will ship via FedEx or DHL upon request, but only if you provide a FedEx or DHL number for us to use when setting up the shipment. We cannot use our FedEx account and bill you for our costs. If you would like your order shipped using FedEx or DHL, you must specify FedEx or DHL and provide your 9-digit FedEx or DHL account number in the “Order Notes” section when placing your order. (Your DHL number should begin with 95- or 96- as DHL uses different numbers for import and export for each account.)

    NOTE: if you request shipping via FedEx or other courier, you will be responsible for any charges incurred for the shipment. The FedEx shipping process does not end if you choose to simply not claim the package or go through customs clearance: the default is that the package is returned to the sender at their expense if arrangements are not made to prevent that. This can amount to hundreds of dollars with the added taxes and fees charged to us for the initial shipment plus the return shipment. You are still responsible for any charges we incur for this shipment, even if you do not clear the package.

    We will only use couriers such as FedEx or DHL when shipping to the UK or Spain under special circumstances due to recurring problems with customs. Packages will be denied entry, returned to us (often at our expense), or detained for prolonged periods pending approval of import permits.

    The CGC has used other couriers in the past. They are not as simple for us to use for us or we have experienced problems with customs, etc. If you do not have access to FedEx or DHL and want to use UPS or other courier, please contact us at cgc@umn.edu prior to placing your order.
  • How do I cite the CGC in publications?
  • Be sure to acknowledge the CGC! Please use the following statement in any publications in which describe experiments for which you used strains obtained from the CGC, including the grant number:

    "Some strains were provided by the CGC, which is funded by NIH Office of Research Infrastructure Programs (P40 OD010440)."
  • Can strains received from the CGC be shared with others?
  • Strains obtained from the CGC may not be redistributed outside of the recipient's organization without our written consent.
    See our Conditions of Use.
  • The phenotype does not match the description of the mutant. What do I do?
  • If you find that there are problems with any strains you receive from the CGC, please notify us as soon as possible. We are a community resource and rely on user feedback to ensure the validity of strains for all users. If you find that the phenotype or genotype of a strain is not as expected, we will do what we can to verify whether the stock we have is correct or not, and get a replacement if necessary. We cannot guarantee strains indefinitely, but if we are notified of a problem in a timely manner we will often send a replacement stock after doing what we can to validate the strain. We do not perform molecular analysis of strains, so we cannot confirm questionable sequencing or PCR results, for example.
  • My research laboratory does not yet have funding. Can I still order C. elegans?
  • If the stocks are needed for academic research or teaching purposes and you do not have grant or institutional funds (including start-up funds) with which to pay your fees, a waiver of the fees may be granted. To be considered for a waiver, send the list of strains requested, a brief summary of your research plans using the strains, and an explanation of your financial situation to us at cgc@umn.edu before placing your order through our site. If your request is approved, we will provide you with a one-time use code to use during checkout so that you are not billed for those strains.
  • I am a high school student, can I order C. elegans?
  • Yes, we do provide strains to high school students. We ask that students include their instructor or adviser on any email correspondence with us. The instructor should contact us at cgc@umn.edu to obtain more information about obtaining a lab code and placing orders.

    Do you have funding available through your school or research program specifically for reagents such as this, or will you (or the students) be paying for the strains out of pocket? We do waive the fees for high school students under some circumstances. If there is not any funding available through the school or program to pay the fees, a waiver may be granted for the required strains. To be considered for a waiver, send your strain request together with a brief explanation of your funding situation before placing your order through our site. If approved, we will provide you with a code to use when placing your order so that you are not billed for the strains.

    Use our website or WormBase to search for mutants that might be interesting to study. Don’t forget to order OP50 to feed your worms and N2 (wild-type) for your control! Other C. elegans resources to help you plan an experiment are listed on our website. Although we can’t keep track of everything on the web that might help you, there are many teachers who have put ideas out there. If you find a website that is particularly helpful, let us know about it!
  • What supplies do I need before I order worms?
  • If you are new to worms, here are a couple links to some introductory materials that you might find helpful:

    http://www.wormbook.org/chapters/www_celegansintro/celegansintro.html
    http://www.wormbook.org/chapters/www_strainmaintain/strainmaintain.html

    The CGC does not provide media or other supplies.
  • My worms arrived dead. What do I do?
  • We do our best to ensure strains are delivered in good condition. Worms are quite resilient, but sometimes the conditions encountered during their travels are too much. Even if you do not see any animals moving on the plate you receive, try moving a ~1cm x 1cm chunk of agar to a new plate with a flame-sterilized scalpel or spatula. There are often starved animals that have burrowed into the agar that will crawl out when moved to a plate with food.

    If you are unable to recover a strain within a few days after transferring to a fresh plate of food, please send us an email with the following information: your name and lab code, the order number, the strain names of the worms you need resent. We will often send a replacement at no cost if notified in a timely manner: Do not place a new order for the strain through our website unless you plan to pay for that new order.
  • My plates are contaminated. What do I do?
  • We don't send plates that are visibly contaminated, but things do sometimes pop up in shipping.


    Elimination of mold by serial transfer

    Mold is easily eliminated by serially transfer ring worms to clean plates 2-3 times over the course of a couple hours. They will slough off mold on their bodies crawling through the lawn of bacteria, and feeding will purge their guts. This is a link to methods chapter that contains a more detailed protocol for eliminating mold: http://www.wormbook.org/chapters/www_strainmaintain/strainmaintain.html

    1. Sterilize a scalpel or spatula in a flame and remove a chunk of the agar from the contaminated plate. Remove the cover of the contaminated plate only as long as necessary.

    2. Place the chunk of agar at the edge of a seeded clean plate. Allow the worms to crawl out of the chunk and across the E. coli OP50 lawn.

    3. Once the worms have crawled a significant distance into the OP50 lawn, pick individual animals with a worm picker and place it on the edge of another clean plate.

    4. Repeat at least 1-2 more times and your stock should be free of mold.

    Elimination of bacteria or yeast contamination by bleaching
    Bacterial contamination happens when you don’t use your very best sterile technique. Here is how you can get your stocks clean again.

    Reagents

    o 5 N NaOH
    o Household bleach (5% solution of sodium hypochlorite)

    Methods

    1. Use contaminated C. elegans stock plates that have many gravid hermaphrodites. Wash the plates with sterile H2O. Pipet the H2O across the plate several times to loosen worms and eggs that are stuck in the bacteria.

    2. Collect the liquid in a sterile 15 ml conical centrifuge tube with cap. Add H2O to total 3.5 ml.

    3. Mix 0.5 ml 5 N NaOH with 1 ml bleach. Make this solution fresh just before use! Add to the centrifuge tube with the worms.

    4. Shake well or vortex the tube for a few seconds. Repeat shaking/vortexing every 2 minutes for a total of 10 minutes.

    5. Spin the tube in a table top centrifuge for 30 seconds at 1300 x g to pellet released eggs.

    6. Aspirate to 0.1 ml.

    7. Add sterile H2O to 5 ml. Shake well or vortex for a few seconds.

    8. Repeat steps 5 and 6.

    9. Use a Pasteur pipet to transfer the eggs in the remaining 0.1 ml of liquid to the edge of a clean NGM plate seeded with an E. coli OP50 lawn.

    The next day the eggs will have hatched and the larvae will have crawled into the E. coli OP50 lawn. Transfer the hatched larvae to a clean NGM plate seeded with a lawn.

    Note that some mutants are sensitive to hypochlorite treatment. If none of the eggs hatch following treatment, decrease the incubation time in step 4, monitoring until the cuticles of gravid adults just burst.



  • Can’t find the answer to your question here?
  • Contact us at cgc@umn.edu Emails are typically answered within 1-2 business days.