Sphaerothecum destruens (ATCC® 50644)

Strain Designations: Dermocystidium-like strain  /  Depositor: K Arkush  /  Biosafety Level: 2

Permits and Restrictions

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Deposited As Rosette agent
Strain Designations Dermocystidium-like strain
Biosafety Level 2

Biosafety classification is based on U.S. Public Health Service Guidelines, it is the responsibility of the customer to ensure that their facilities comply with biosafety regulations for their own country.

Product Format frozen
Storage Conditions Frozen Cultures:
-70°C for 1 week; liquid N2 vapor for long term storage

Freeze-dried Cultures:

Live Cultures:
See Protocols section for handling information
Type Strain no
Comments CHSE-214 cells (ATCC® CRL-1681™) are no longer available for domestic or international distribution due to being listed as a threatened species on the endangered species list. ASK (ATCC® CRL-2747™) is the only other salmonid cell line available at ATCC, but its capacity to support the growth of Sphaerothecum destruens has not been tested at ATCC.
Growth Conditions Temperature: 15°C
Atmosphere: Microaerophilic
Culture System: CHSE-214 cells (ATCC® CRL-1681™)
Cryopreservation Reagents
Cryoprotective Solution
DMSO 2.0 mL
Fresh growth medium (7.5% serum) 8.0 mL

Harvest and Preservation

  1. To harvest the Sphaerothecum culture, detach any remaining tissue culture cells (infected and uninfected) by scraping the surface of the flask with a cell scraper.
  2. Transfer the cell suspension (including parasites) to 15 mL plastic centrifuge tubes. Centrifuge at 1000 x g for 10 min.
  3. Remove all but 0.5 mL of the supernatant from each tube, resuspend the cell pellets, and pool them to a single tube.
  4. Optionally pass the resulting cell suspension through a syringe equipped with a 27 gauge 1/2 in needle to break up any remaining cells.
  5. Adjust the parasite concentration to 2.0 - 4.0 x 107 cells/mL with fresh medium or PBS.
    NOTE: If the concentration of parasites is too low, centrifuge at 1000 x g for 10 min and resuspend in the volume of fresh medium or PBS required to yield the desired concentration.
  6. Prepare a cryoprotective solution containing 20% (v/v) DMSO and 7.5% (v/v) HIFBS in fresh medium or PBS.
  7. Mix the cell preparation and cryoprotective solution in equal portions. The final concentration will be 1.0 - 2.0 x 107 cells/mL, 10% DMSO, and 7.5% HIFBS. The time from the mixing of the cell preparation and cryoprotective solution to the start of the freezing process should be no less than 15 min. and no more than 30 min.
    NOTE: To prevent culture contamination, penicillin-streptomycin solution (ATCC® 30-2300™) may be added to a final concentration of 50 to 100 I.U./mL penicillin and 50 to 100 µg/mL streptomycin.
  8. Dispense in 0.5 mL aliquots to 1.0-2.0 mL sterile plastic screw-capped cryules (special plastic vials for cryopreservation).
  9. 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.)
  10. Store frozen ampules in either the vapor or liquid phase of a nitrogen refrigerator.
  11. 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.  Do not leave ampule in water bath after thawed.
  12. Immediately after thawing, aseptically transfer contents to a T-25 tissue culture flask containing a fresh monolayer of cells (ATCC® CRL-1681™) and 10 mL ATCC® 30-2003™ with 7.5% (v/v) HIFBS.
  13. Outgas the flask for 10 seconds with a 95% air, 5% CO2 gas mixture.
  14. Incubate in a 15°C CO2 incubator with the cap screwed on tightly.
  15. Once the culture is established, follow the protocol for maintenance of culture.

Name of Depositor K Arkush

Arkush KD, et al. Observations on the life stages of Sphaerothecum destruens n. g., n. sp., a mesomycetozoean fish pathogen formally referred to as the rosette agent. J. Eukaryot. Microbiol. 50: 430-438, 2003. PubMed: 14733435

Notice: Necessary PermitsPermits

These permits may be required for shipping this product:

  • Customers located in the state of Hawaii will need to contact the Hawaii Department of Agriculture to determine if an Import Permit is required. A copy of the permit or documentation that a permit is not required must be sent to ATCC in advance of shipment.
Basic Documentation