Live Materials - Frequently Asked Questions

For live material shipping rates, see Shipping & Delivery page.

NOTE: Frog Hatchery Kits have their own FAQ listing. This includes answers to 20 basic questions about growing frog tadpoles.
Instructions for feeding Xenopus frogs

Nasco Policy

Nasco guarantees live delivery. Once the customer receives the live specimen, it is that customer’s responsibility to safely maintain the organism. If the organism is dead upon arrival, Nasco will either replace or credit (our choice). Any damage must be reported within 48 hours of receipt.

Nasco ships most live organisms via FedEx®. Most are shipped via FedEx® Next Day or FedEx® Second Day Air. We monitor national temperature trends on a daily basis and will select the best option for your destination and for the live specimens on your order.

That varies widely. It depends on where you are located, how hardy the organisms are, how large the shipping carton needs to be to protect them, and what kind of weather has been predicted. Most live shipments are comparatively lightweight, but considered “oversized” by the cargo service. The charges are “dimensionalized.” Air freight charges are calculated not only by weight, but also by how much space the carton takes up in the airplane cargo hold.

We ship live materials Monday through Thursday, but aim for shipment early in the week if possible. We do not deliver on the weekends.

We cannot ship for Monday delivery. It is just unsafe for the living organisms to ship them over the weekend. The potential for hazardous delays is too great.

Basic instructions are included that tell you what to do with the organisms until class time. Customers should refer to their teacher’s guide or experimental protocol for detailed instructions. Information is also available at your library and on the Internet. Nasco also sells books concerning live materials in the classroom.

Our Wisconsin laboratory produces most of our specimens (i.e. Xenopus frogs). Professional collectors throughout the country supply other animals (i.e. anoles lizards). The food industry also supplies some specimens (i.e. crayfish). All specimens are produced or collected in accordance with government rules and regulations.

Most are, but some specimens are seasonal by nature and only available at certain times of the year. All orders of live specimens are subject to availability at the time shipment is requested. Any items that are seasonal will have general comments about that in their description. Note, however, that every year is unique. Some supplies follow natural cycles, but all availability may be subject to events such as droughts, floods, excessive cold, or excessive heat.

Here is a very general list of seasonal live items. Time periods are approximate only. Weather conditions in the collecting area can affect the time period.

Available only when weather is cold:

  • Leopard Frog Rana (Lithobates) pipiens eggs (LM00904M) - available November through March (approximately).
  • Leopard Frog Rana (Lithobates) pipiens (LM00222M, LM00662M, LM00663M, LM00664M, LM00689M) - available late October through March (approximately).
  • Bess Beetles (LM00795(B)M) - available in winter months only, about November through March.
  • We will automatically substitute millipedes for out-of-season shipments.
  • Crayfish (LM00043M, LM00044M) - ship best when weather is cold. Usually available September through April.

These animals are found in warm climates and may not be available in extreme cold weather, so please plan accordingly:

  • “Chameleon” Lizards (Anolis carolinensis) (LM00229M)
  • Tree Hermit Crabs (Coenbita clypeatus) (LM00292M)
  • Green Tree Frog (Hyla cinerea) (LM00772M)
  • Mediterranean Gecko Lizards (Hemidactylus turcicus) (LM00773M)

No! Releasing classroom pets or surplus laboratory specimens into the wild may be prohibited by law in your state and, in all cases, is unethical. Once released into the wild, any of these unwanted plants or animals can have a negative impact on native species and ecosystems.

This can...

  • Introduce harmful pathogens and parasites
  • Increase competition with native, resident species for resources
  • Cause predation on native species
  • Cause degradation of native/resident animal population’s gene pools
  • Give the animal to another responsible teacher or classroom
  • Keep it as a classroom pet
  • Donate it to your local natural history museum or science center
  • Trade it in for alternative product at a responsible pet shop
  • If live material cannot be maintained with security in your classroom or laboratory, it should be humanely euthanized

Yes, Nasco can ship live specimens internationally. Each order request is handled on an individual basis. Extra permits needed. Some limits apply, country by country. Contact our International Sales Department.


Microscopic organisms are sold in classes of 30. This means they contain enough organisms for typical classroom microscope activity for 30 students. Most jars of protozoa or algae contain hundreds, if not thousands, of individual organisms. It is the same for tubes of bacteria or fungi. You should have enough living material for a typical microscope activity for a class of 30 students. For slightly larger invertebrate organisms such as Planaria, Daphnia, or Hydra, animals are actually counted into their containers and will have 30, 60, or 120 specimens, as labeled.

They are generally in best condition the day you receive them. You should time your lab to use them as soon as possible after you receive them. However, many cultures can last for several days, or even weeks, if kept properly. After that, the microorganisms will run out of the food that was included in their shipping container. If you choose to keep the cultures going, you will need to subculture them into fresh growth media.

Nasco offers growth media: SB07568(LM)M Paramecium medium, SB07564(LM)M Amoeba medium, and SB07566(LM)M Euglena medium. These are only growth media. They do not contain live organisms, just necessary nutrients for them. You would need to inoculate them with live cultures to make more organisms.

It’s the law. Some cultures are more problematic than others. The list of government-restricted organisms continues to grow. It is more likely that a university laboratory will have the proper equipment and oversight to safely work with some bacteria than the typical high school classroom, let alone a home school situation or science fair project. Though none of Nasco’s bacterial cultures are pathogenic, ALL cultures should be handled with the same level of stringent laboratory hygiene. Any customer working with bacteria should be following established microbiology protocols and strict sanitary technique.

Prepared media has already been cooked, dispensed into tubes or plates, and then sterilized. It is ready to use. It should be kept refrigerated until use. Then all you need to do is inoculate with your bacteria sample.

Agar powder is the dehydrated form. It does not need to be refrigerated until you make it into the gel. Most agar is available in a dehydrated powdered form, though Nasco does offer several prepared gel types. When powdered agar is prepared, it resembles clear gelatin. Each type of bacteria or fungi has its own preferred food and optimal temperature. Customers should consult their experimental protocol or lab manual to determine what type they need.

To make agar powder into a gel, the agar is added to distilled water and cooked according to directions, placed into culture tubes or plates, then sterilized either in an autoclave or pressure cooker (15 lbs. pressure for 15 minutes). Once you have the agar in this useful gel form, it should be refrigerated. It is then best used within 2 to 4 weeks.

Most grow on either tryptic soy agar or nutrient agar.

Consult your experimental protocol or manual. Those guidelines should tell you what you need. Anyone working with bacteria or fungi should be following established microbiology guidelines.

Plain agar agar powder lacks nutrients. It is good for sprouting seeds and watching root development, but it contains no food to feed bacteria. It is not suitable for growing bacteria unless you add nutrients such as dextrose, beef extract, peptone, etc.

Bacterial cultures can be destroyed by autoclaving/sterilization (15 lbs. pressure for 15 minutes) or fill the inside of the culture tube with commercial bleach or isopropyl alcohol and soak for 15 minutes. Wrap in a plastic bag and dispose of it in a regular garbage receptacle.


For Nasco, all of our live grassfrogs are Northern Leopard Frogs. For other biological supply companies, that may collect frogs elsewhere, their “grassfrogs” may be some other species. “Grassfrog” is a very general term that could be many varieties of the genus Rana, collected from many geographical locations. Our live frogs are collected in the Great Lakes area. The only live “grassfrogs” we carry are Rana (Lithobates) pipiens, also known as the Northern Leopard Frog.

Body only: tip of the nose to the end of the spine; measurement does NOT include the legs.

  • Xenopus laevis frogs (African Clawed Frogs) reach maturity at about 2 years of age. That equates to item LM00715M 7.5 cm to 9 cm males, and LM00535M or LM00531M 9+ cm females. Any frogs smaller than that are probably juveniles. They are not yet mature. Xenopus frogs can be bred any time of the year. These frogs are induced to breed by injecting them with a hormone - Human Chorionic gonadotropin (HCG).
  • Xenopus tropicalis frogs (Silurian Frogs or Dwarf African Frogs) are reported to reach maturity at 6 months of age and that is the benchmark we use. This would be LM00822M Xenopus tropicalis males and LM00823M Xenopus tropicalis females. However, we find them more reproductively reliable after they reach 9+ months of age. Like Xenopus laevis frogs, Xenopus tropicalis can be bred any time of the year by using hormone injections with Human Chorionic gonadotropin.
  • Rana pipiens frogs (Northern Leopard Frogs) are field-collected and not reared in our lab, so we do not know their age. Mature sizes would be LM00664M 3"-3½" frog, LM00222M female, and LM00689M male. Through the winter months, we hold these animals under artificial hibernation in our facility. These frogs are seasonal, typically available from late autumn through late March. You can induce ovulation and conduct in vitro fertilization with mature animals in November through March. After that, these frogs enter their natural spawning period and are “off limits.” To induce ovulation during the winter months, you can use fresh pituitary glands extracted from “donor” frogs, or use Pituitary Extract, made specifically for Rana pipiens frogs.

Xenopus frogs are not native to this continent. They come from Africa. Some states have climates that closely resemble parts of Africa. There is a concern that if these Xenopus frogs escaped into the local environment, they would out-compete native amphibians for precious food and habitat. The following states require permits to import Xenopus frogs (this list is subject to change as state regulations change): Alaska, Arizona, California, Hawaii, Kentucky, Louisiana, Montana, Nevada, New Jersey, Oregon, Utah, Virginia, North Carolina, and Washington.

The LM00535M frog is a large, “virgin” female frog that has never ovulated. The LM00531M frog has been given an injection of HCG hormone to induce ovulation, thereby verifying functional ovaries. We then hold that pre-tested female for at least 4 weeks to allow time for her to rebuild stage 5 and some stage 6 oocytes in her ovaries. Then she is ready to ship.

Both animals are sexually mature Xenopus laevis frogs. Both have a high probability of producing eggs, however, due to variables beyond our control, Nasco cannot guarantee either quantity or quality of oocytes that any frog may contain in her ovaries.

Researchers that need stage 6 oocytes may want to order the untested female, LM00535M. She has never been ovulated and should hold her full allotment of oocytes. But because she has never shed her eggs, some may be over-ripe.

Researchers that want stage 5+ oocytes may want to order the pre-tested female, LM00531M. Because she ovulated recently, she may hold fewer eggs than an untested female. However, they should be new ones. She should have stage 5 and probably some stage 6 oocytes.

  • The Leopard Frog, Rana (Lithobates) pipiens - is a native of North America. It is an opportunistic scavenger when a tadpole and is found in freshwater ponds. It will metamorphose into a land predator that hunts and eats small insects and other VERTEBRATES in marshes and meadows. It is no longer totally aquatic. As a frog, it requires both land area and water area. It also requires live prey items. Food must move for the frog to identify a meal. You can feed them live redworms, crickets, fruit flies, etc. From the fertilized egg to metamorphosis takes about 3 months. This frog reaches sexual maturity at about 2 years of age. Natural breeding takes place in April. The animals breed once per year. In the lab, ovulation can be artificially induced one time during the winter months.
  • The African Clawed Frog (Xenopus laevis) is a native of southern Africa. While a tadpole, it is a filter-feeding scavenger in freshwater ponds. It will metamorphose into a totally aquatic frog that scavenges for food particles. You can feed them dry food pellets such as Nasco Frog Brittle. From fertilized egg to metamorphosed frog takes 2 months. They take about two years to reach sexual maturity. In the wild, natural breeding can take place at any time of the year, whenever the rains come. In the lab, they can be induced to breed any month of the year. If properly maintained, they can be bred every 3 to 4 months.

It is federal law. Turtles cannot be shipped through normal means. They must be sent via airfreight and that is expensive.

Always use biologically sound water. If you choose to use municipal water, remove any chlorine or chloramine first. Many chlorine remover solutions are available. AmQuel® Water Conditioner (SB13232M) is a good one. Chlorine is fairly unstable and dissipates from the water. In the past, one just needed to aerate city water for 48 hours and the chlorine would disappear. Now many municipal water departments have switched to more stabile chloramine treatments. Chloramine does not dissipate readily and is very toxic to aquatic animals.

Maybe. But you might introduce unanticipated microorganisms to the project, including parasites.

You could add 1 unit of SA06355(LM)M Invertebrate Culture Solution Concentrate to 5 liters of your own distilled water to create 5 liters of buffered artificial spring water, or you could use bottled drinking water or bottled spring water.

Please allow 2 to 6 weeks for redemption. However, several other factors may also affect when we can ship:

  • If night time temperatures fall below freezing, either here or where you are, we may need to delay shipment. We monitor national weather trends and make shipping decisions accordingly.
  • If daytime temperatures exceed 83° F, either here or where you are, we may need to delay shipment.
  • We do not ship during weeks that contain a postal holiday. We have found the chance for hazardous delays is too great. It would be unsafe for the animals.
  • Are you located in a “restricted” state? Restricted states are: AK, AZ, CA, HI, KY, LA, MT, NV, NJ, NC, OR, UT, VA, and WA (this list subject to change). If you are located in any of these states, please plan your frog project for the winter months. Your state laws restrict which type of frog you can receive. The only frog eggs we can send to you are from the Leopard Frog (Rana pipiens), and those frogs only produce eggs during the winter time. We can only ship to you during the winter months of November through March. Please send your coupon to Nasco between November and the end of February. That gives us time to prepare and ship your animals before the end of March deadline. Note that Utah (UT), Hawaii (HI), and Alaska (AK) all have extra laws limiting animal shipment. We can’t ship ANY frogs to those three states, no matter what time of year. Sorry.
  • Restricted-state coupons received out of season, April through October, will be sent back to the customer. You can re-submit the coupon sometime during the winter months, when animals suitable for your area are available.
  • The final variable is the frog. Sometimes they produce eggs, sometimes they don’t. Ultimately, whether or not we have eggs any given week is up to the animals. They are a product of nature. They can be encouraged to produce eggs, but there is no guarantee that they will.