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1. To achieve the best results set up cultures with several different inocula (e.g. 0.25 ml, 0.5 ml, 1.0 ml).  Harvest cultures and pool when the culture that received the lowest inoculum is at or near peak density.
2. If the cell concentration exceeds the required level do not centrifuge, but adjust the concentration to between 2 x 10⁶ and 2 x 10⁷cysts/ml with fresh medium.  If the concentration is too low, centrifuge at 600 x g for 5 min and resuspend the pellet in the volume of fresh medium required to yield the desired concentration.
3. While cells are centrifuging prepare a 15% (v/v) solution of sterile DMSO as follows:  Add the required volume of DMSO to a glass screw-capped test tube and place it in an ice bath.  Allow the DMSO to solidify.  Add the required volume of refrigerated medium.  Dissolve the DMSO by inverting the tube several times.
   *NOTE: If the DMSO solution is not prepared on ice, an exothermic reaction will occur that may precipitate certain components of the medium.
4. Mix the cell preparation and the DMSO in equal portions. Thus, the final concentration will be between 10⁶ and 10⁷ cells/ml and 7.5% (v/v) DMSO. The time from the mixing of the cell preparation and DMSO stock solution before the freezing process is begun should be no less than 15 min and no longer than 30 min.
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 the vials in a controlled rate freezing unit.  From room temperature cool at -1°C/min to -40°C.  If the freezing unit can compensate for the heat of fusion, maintain rate at        -1°C/min through the heat of fusion.  At -40°C plunge 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. The frozen preparations are stored in either the vapor or liquid phase of a nitrogen freezer.
8. To establish a culture from the frozen state place an ampule in a water bath set at 35°C (2-3 min). Immerse the vial just sufficient to cover the frozen material. Do not agitate the vial.
9. Immediately after thawing, aseptically remove the contents of the ampule and inoculate into 5 ml of fresh ATCC medium 712 in a T-25 tissue culture flask or plastic 16 x 125 mm screw-capped test tube.  Incubate at 25°C.

Martinez AJ, et al. Experimental pneumonitis and encephalitis caused by Acanthamoeba in mice: pathogenesis and ultrastructural features. J. Infect. Dis. 131: 692-699, 1975. PubMed: 48530

Chung DI, et al. Biochemical and molecular characterization of a strain KA/S2 of Acanthamoeba castellanii isolated from Korean soil. Korean J. Parasitol. 34: 79-85, 1996. PubMed: 8820744

Daggett PM, et al. Distribution and possible interrelationships of pathogenic and nonpathogenic Acanthamoeba from aquatic environments. Microb. Ecol. 8: 371-386, 1982.

Byers TJ, et al. Genes of Acanthamoeba: DNA, RNA and protein sequences (a review). J. Protozool. 37: 17S-25S, 1990. PubMed: 1701831

Daggett PM, et al. A molecular approach to the phylogeny of Acanthamoeba. Biosystems 18: 399-405, 1985. PubMed: 4084681

Kong HH, et al. Mitochondrial DNA restriction fragment length polymorphism (RFLP) and 18S small-subunit ribosomal DNA PCR-RFLP analyses of Acanthamoeba isolated from contact lens storage cases of residents in southwestern Korea. J. Clin. Microbiol. 40: 1199-1206, 2002. PubMed: 11923331

Reveiller FL, et al. Species specificity of a monoclonal antibody produced to Naegleria fowleri and partial characterization of its antigenic determinant. Parasitol. Res. 86: 634-641, 2000. PubMed: 10952262