Entamoeba dispar Brumpt (ATCC® PRA-368)

Strain Designations: NIH:0581:1  /  Depositor: LS Diamond  /  Biosafety Level: 1

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Deposited As Entamoeba histolytica Schaudinn
Strain Designations NIH:0581:1
Biosafety Level 1

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.

Isolation Human
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
Medium ATCC® Medium 1171: TYGM-9 medium
Growth Conditions
Temperature: 35°C
Atmosphere: Microaerophilic
Culture System: Xenic
Cryopreservation Reagents
CPMB-5 Cryoprotective Solution
DMSO, 1.0 mL
2.5 M Sucrose, 0.8 mL
L-Cysteine/Ascorbic Acid Solution, 0.2 mL
CPMB-2 Basal Solution, 6.0 mL
HIBS, 2.0 mL

CPMB-2 Basal Solution
Yeast Extract, 60.0 g
K2HPO4, 1.0 g
KH2PO4, 0.6 g
NaCl, 2.0 g
Distilled water, 1.0 L
Autoclave for 15 minutes.

L-Cysteine/Ascorbic Acid Solution
L-Cysteine-HCL, 1.0 g
Acorbic Acid, 0.1 g
Distilled water, 10.0 mL

Add 9.0 mL of distilled water to a 20 mL beaker and dissolve the first two components.  While stirring, adjust the pH to 7.2 with 10N NaOH (approximately 0.7 mL).  Adjust final volume to 10 mL with distilled water and filter sterilize. Solution should be used soon after preparation.  Discard any unused solution.

Harvest and Preservation
  1. Harvest cells from several cultures which are in the late logarithmic to early stationary phase of growth.  Place culture vessels on ice for 10 min.
  2. Invert tubes 20 times and centrifuge at 200 x g for 5 min.        
  3. While cells are centrifuging, prepare the cryoprotective solution. 
    1. Place the DMSO in a 16 x 125 mm screw-capped tube and ice until solidified.
    2. Add 0.8 mL of the 2.5 M Sucrose solution, remove from ice and invert until the DMSO is liquefied.  Return to ice bath.
    3. Add 0.2 mL of the L-Cysteine/Ascorbic Acid solution to the DMSO solution and mix.
    4. Add 6.0 mL of the CPMB #2 Basal solution and mix.
    5. Add 2.0 mL heat-inactivated bovine serum and mix.
  4. Resuspend the cell pellets and pool to a final volume of approximately 10 mL with the supernatant.  Make a determination of the cell density and adjust the concentration of the cells between 5 x 105/mL - 1 x 106/mL using fresh medium.  If the cell concentration is below 5 x 106/mL, centrifuge the cell suspension and resuspend the pellet in a volume that will yield the desired concentration.
  5. After the cell concentration is adjusted, centrifuge as in step 2.
  6. Remove as much supernatant as possible and determine the volume removed.
  7. Resuspend the cell pellet with a volume of the cryoprotective solution equal to the volume of the supernatant removed.  Invert the tube several times to obtain a uniform cell density.
  8. Dispense 0.5 mL aliquots into 1.0 - 2.0 mL plastic sterile 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.
  10. Store ampules in a liquid nitrogen refrigerator until needed.
  11. One day before thawing a frozen ampule inoculate two tubes of ATCC medium 1171 with the bacterial flora only.  Incubate the tube on a 15° horizontal slant at 35°C.
  12. On the following day combine 4.1 mL of the bacterized medium 1171 prepared in step 11 with 0.9 mL of HIBS (heat-inactivated bovine serum) to produce 5 mL of medium enriched with 20% serum.  Invert gently several times to mix.
  13. Remove the frozen ampule from liquid nitrogen and flame gently at the base of the cap.  Remove the cap and aseptically add 0.5 mL of the serum-enriched medium prepared in step 12.  Place in a 35°C water bath until thawed (2-3 min).  Note:  Manipulations of the ampule before placing in the water bath should be done as quickly as possible to avoid warming of the contents at a suboptimal rate.
  14. Transfer contents of the thawed ampule to a one-dram screw-capped vial (vial holds approximately 4.0 mL).
  15. Add 2.5 mL of serum-enriched medium prepared in step 12 to the vial in dropwise fashion.  Tighten the cap and incubate on a 15° horizontal slant at 35°C for 2-3 hours.
  16. Ice the vial for 10 minutes, then invert gently 10 times. Centrifuge the vial at 100-200 x g for 5 min.
  17. Aspirate the supernatant leaving approximately 0.5 mL.  Note:  Do not aspirate the pelleted material.
  18. Replace the supernatant with 3.0 mL of the bacterized medium 1171 prepared in step 11.
  19. Incubate the vial on a 15° horizontal slant at 35°C with the cap screwed on tightly.  Observe the culture daily and transfer when many trophozoites are observed (i.e., early stationary phase).
Name of Depositor LS Diamond

Clark CG, Diamond LS. Ribosomal RNA genes of 'pathogenic' and 'nonpathogenic' Entamoeba histolytica are distinct. Mol. Biochem. Parasitol. 49: 297-302, 1991. PubMed: 1685555

Clark CG, Diamond LS. Intraspecific variation and phylogenetic relationships in the genus Entamoeba as revealed by riboprinting. J. Eukaryot. Microbiol. 44: 142-154, 1997. PubMed: 9109261

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