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Helgoeca nana Leadbeater


Product category
Strain designation
3/25/81 NB(2)
Type strain
Isolation source
Lower Narragansett Bay
Geographical isolation
United States; Rhode Island
Product format
Storage conditions
-80°C or colder for 1 week, vapor phase of liquid nitrogen for long-term storage
Mission Collection Item
This is a Mission Collection Item


Biosafety Icon Biosafety Level 1

ATCC determines the biosafety level of a material based on our risk assessment as guided by the current edition of Biosafety in Microbiological and Biomedical Laboratories (BMBL), U.S. Department of Health and Human Services. It is your responsibility to understand the hazards associated with the material per your organization’s policies and procedures as well as any other applicable regulations as enforced by your local or national agencies.

ATCC highly recommends that appropriate personal protective equipment is always used when handling vials. For cultures that require storage in liquid nitrogen, it is important to note that some vials may leak when submersed in liquid nitrogen and will slowly fill with liquid nitrogen. Upon thawing, the conversion of the liquid nitrogen back to its gas phase may result in the vial exploding or blowing off its cap with dangerous force creating flying debris. Unless necessary, ATCC recommends that these cultures be stored in the vapor phase of liquid nitrogen rather than submersed in liquid nitrogen.

Detailed product information


Originally deposited as Acanthoecopsis unguiculata. Classified as Helgoeca nana based on ultrastructural and phylogentic analyses

Handling information

Instruction for complete medium

Media: ATCC® medium 2417 Marine Choanoflagellate medium (augmented with two sterile rice grains added to culture flask) inoculated with Klebsiella pneumoniae subsp. pneumoniae (ATCC 700831)

Alternate media: ATCC® medium 1405 HESNW medium, ATCC Medium 1361 Marine Flagellate medium (both augmented with two sterile rice grains added to culture flask and inoculated with Klebsiella pneumoniae subsp. pneumoniae (ATCC 700831)

Culture system
Grown with mixed bacteria
Handling procedure

Storage and Culture Initiation

Frozen ampules packed in dry ice should either be thawed immediately or stored in liquid nitrogen.  If liquid nitrogen storage facilities are not available, frozen ampules may be stored at or below -70°C for approximately one week.  Do not under any circumstance store frozen ampules at refrigerator freezer temperatures (generally -20°C).  Storage of frozen material at this temperature will result in the death of the culture.

Note: Care must be taken to maintain this organism at 4°C at all times. All media used should be pre-chilled to 4°C. The culture may be briefly examined under the microscope at room temperature but every effort should be made to keep the organism at 4°C (e.g. transport culture on ice to and from the incubator)

  1. To thaw a frozen ampule, place it in a 35°C water bath such that the lip of the ampule remains above the water line. Thawing time is approximately 2 to 3 minutes.  Do not agitate the ampule.  Care must be taken Do not leave ampule in water bath after it is thawed.
  2. Add the thawed contents to a T-25 flask containing 10 ml of  of chilled  ATCC medium 2417 (augmented with two sterile rice grains added to culture flask)  bacterized with Klebsiella pneumoniae subsp. pneumoniae (ATCC 700831).
  3. Immediately incubate flask at 4°C with the cap tightly sealed. 

Culture maintenance
Note: Care must be taken to maintain this organism at 4°C at all times.

Subculture every two  to three  weeks to a fresh T-25 flask of bacterized medium in the following manner:

  1. Vigorously agitate the flask and aseptically transfer 0.5 ml from a growing culture to a T-25 tissue culture flask containing 10.0 ml of ATCC medium 2417 (augmented with two sterile rice grains added to culture flask)  bacterized with Klebsiella pneumoniae subsp. pneumoniae (ATCC® 700831)
  2. Incubate flask at 4°C with the cap on tightly.
Reagents for cryopreservation

Cryoprotective Solution
DMSO, 1.5 ml
Fresh growth medium w/o bacteria, 8.5 ml

Note: Care must be taken to maintain this organism at 4°C at all times.  Media and cell suspension should be kept on ice during entire process.

  1. Mix the components in the order listed. When the medium is added to the DMSO the solution will warm up due to chemical heat.  Chill to 4°C.
  2. Harvest cells from a culture that is at or near peak density by filtration and centrifugation at 800 x g for 5 min.
  3. Adjust the concentration of cells at least 2 x 106/ml in fresh medium.
  4. Mix the cell preparation and the cryoprotective solution in equal portions.
  5. Dispense in 0.5 ml aliquots into 1.0 - 2.0 ml sterile plastic screw-capped cryules (special plastic vials for cryopreservation).
  6. Place vials in a controlled rate freezing unit. From room temperature cool at -1°C/min to -40°C. If freezing unit can compensate for the heat of fusion, maintain rate at -1 C/min through heat of fusion. At -40°C plunge ampules into liquid nitrogen. Alternatively, place the vials in a Nalgene 1°C freezing apparatus.  Place the apparatus at -80°C for 1.5 to 2 hours and then plunge ampules into liquid nitrogen.  (The cooling rate in this apparatus is approximately -1°C/min.)  
  7. Ampules are stored in either the vapor or liquid phase of a nitrogen refrigerator.
  8. To establish a culture from the frozen state place the vial in a 35°C water bath.  Immerse the vial to a level just above the surface of the frozen material. Do not agitate the vial.  Do not leave in water bath after thawing. Aseptically remove the contents of the ampule and inoculate into a T-25 tissue culture flask containing 10 ml chilled ATCC medium 2417 bacterized with Klebsiella pneumoniae subsp. pneumoniae (ATCC®  700831).
  9. Incubate at 4°C with the cap screwed on tightly.
  10. Once the culture is established, vigorously agitate the flask and aseptically transfer 0.5 ml to 10.0 ml of bacterized ATCC medium 2417.
  11. Follow the protocol for maintenance of culture.


Deposited as
Acanthoecopsis unguiculata Thomsen
PG Davis
Type of isolate
Year of origin

Legal disclaimers

Intended use
This product is intended for laboratory research use only. It is not intended for any animal or human therapeutic use, any human or animal consumption, or any diagnostic use.

The product is provided 'AS IS' and the viability of ATCC® products is warranted for 30 days from the date of shipment, provided that the customer has stored and handled the product according to the information included on the product information sheet, website, and Certificate of Analysis. For living cultures, ATCC lists the media formulation and reagents that have been found to be effective for the product. While other unspecified media and reagents may also produce satisfactory results, a change in the ATCC and/or depositor-recommended protocols may affect the recovery, growth, and/or function of the product. If an alternative medium formulation or reagent is used, the ATCC warranty for viability is no longer valid.  Except as expressly set forth herein, no other warranties of any kind are provided, express or implied, including, but not limited to, any implied warranties of merchantability, fitness for a particular purpose, manufacture according to cGMP standards, typicality, safety, accuracy, and/or noninfringement.


This product is intended for laboratory research use only. It is not intended for any animal or human therapeutic use, any human or animal consumption, or any diagnostic use. Any proposed commercial use is prohibited without a license from ATCC.

While ATCC uses reasonable efforts to include accurate and up-to-date information on this product sheet, ATCC makes no warranties or representations as to its accuracy. Citations from scientific literature and patents are provided for informational purposes only. ATCC does not warrant that such information has been confirmed to be accurate or complete and the customer bears the sole responsibility of confirming the accuracy and completeness of any such information.

This product is sent on the condition that the customer is responsible for and assumes all risk and responsibility in connection with the receipt, handling, storage, disposal, and use of the ATCC product including without limitation taking all appropriate safety and handling precautions to minimize health or environmental risk. As a condition of receiving the material, the customer agrees that any activity undertaken with the ATCC product and any progeny or modifications will be conducted in compliance with all applicable laws, regulations, and guidelines. This product is provided 'AS IS' with no representations or warranties whatsoever except as expressly set forth herein and in no event shall ATCC, its parents, subsidiaries, directors, officers, agents, employees, assigns, successors, and affiliates be liable for indirect, special, incidental, or consequential damages of any kind in connection with or arising out of the customer's use of the product. While reasonable effort is made to ensure authenticity and reliability of materials on deposit, ATCC is not liable for damages arising from the misidentification or misrepresentation of such materials.

Please see the material transfer agreement (MTA) for further details regarding the use of this product. The MTA is available at

Permits & Restrictions

Import Permit for the State of Hawaii

If shipping to the U.S. state of Hawaii, you must provide either an import permit or documentation stating that an import permit is not required. We cannot ship this item until we receive this documentation. Contact the Hawaii Department of Agriculture (HDOA), Plant Industry Division, Plant Quarantine Branch to determine if an import permit is required.



Curated Citations

Wainright PO, et al. Monophyletic origins of the metazoa: an evolutionary link with fungi. Science 260: 340-342, 1993. PubMed: 8469985

Leadbeater BSC, et al. A new genus, Helgoeca gen. nov., for a nudiform choanoflagellate. Eur. J. Protistol. 44:227-237, 2008. PubMed: 18403187

Carr M, et al. Molecular phylogeny of choanoflagellates, the sister group to Metazoa. Proc. Natl. Acad. Sci. USA. 105: 16641-16646, 2008. PubMed: 18922774

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