Giardia intestinalis (Lambl) Alexeieff (ATCC® 50580)

Strain Designations: GS  /  Depositor: TE Nash  /  Biosafety Level: 2

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Strain Designations GS
Enteric Research
Food and waterborne pathogen research
Biosafety Level 2
Product Format frozen
Type Strain no
Isolate variation in excretory/secretory products and antigens
Size variation in homologous chromosomes in different strains
Enzyme-linked immunosorbent assay for antigen
Cysteine-rich variant surface proteins
Experimental human infection
Cytotoxicity of monoclonal antibodies
Antigenic variation
Purification of variant-specific surface protein
Epitope variability in susceptibility to proteases
Variant specific epitopes
RFLP analysis of DNA
Medium Medium 2155: LYI Giardia Medium (filtered)
Growth Conditions
Temperature: 35.0°C
Duration: axenic; anaerobic

1.   Harvest cells from a culture that is at or near peak density. To detach cells from the wall of the culture tubes, place on ice for 10 minutes.  Invert tubes several times until the majority of the cells are in suspension.  Centrifuge tubes at 800 x g for 5 minutes. 

2.   Adjust the concentration of cells to 2 x 107/ml in fresh medium.

3.  Before centrifuging prepare a 24% (v/v) solution of sterile DMSO in fresh medium containing 8% (w/v) sucrose.  The solution is prepared as follows:

a) Add 10.5 g sucrose to 10 ml of fresh medium and filter sterilize through a 0.2 mm filter;

b) Add 2.4 ml of DMSO to an ice cold 20 x 150 mm screw-capped test tube;

c) Place the tube on ice and allow the DMSO to solidify (~5 min) and then add 7.6 ml of ice cold medium prepared in step 3a.  The final concentration will be 24% (v/v) DMSO and 8% (w/v) sucrose;

d) Invert several times to dissolve the DMSO;

e) Allow to warm to room temperature.

4.   Mix the cell preparation and the cryoprotective agent, prepared in step 3, in equal portions. Thus, the final concentration will equal 12% (v/v) DMSO + 4% sucrose (w/v) and 107 cells/ml. 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


7.  The frozen preparations should be stored in either the vapor or liquid phase of a nitrogen refrigerator. Frozen preparations stored below -130°C are stabile indefinitely. Those stored at temperatures above -130°C are progressively less stabile as the storage temperature is elevated.

8.   To establish a culture from the frozen state place an ampule in a water bath set at 35°C. Immerse the vial just to a level just above the surface of the frozen material. Do not agitate the vial.

9.   Immediately after thawing, do not leave in the water bath, aseptically remove the contents of the ampule and inoculate a 16 x 125 mm screw-capped test tube containing 13 mls of ATCC medium PRA-2695.

10.          Incubate the culture on a 15° horizontal slant at 35°C.

Name of Depositor TE Nash
Special Collection NCRR Contract

Nash TE, et al. Restriction-endonuclease analysis of DNA from 15 Giardia isolates obtained from humans and animals. J. Infect. Dis. 152: 64-73, 1985. PubMed: 2409186

Adam RD, et al. The Giardia lamblia trophozoite contains sets of closely related chromosomes. Nucleic Acids Res. 16: 4555-4567, 1988. PubMed: 2837738

Nash TE, et al. Usefulness of an enzyme-linked immunosorbent assay for detection of Giardia antigen in feces. J. Clin. Microbiol. 25: 1169-1171, 1987. PubMed: 3611309

Aggarwal A, et al. Cysteine-rich variant surface proteins of Giardia lamblia. Mol. Biochem. Parasitol. 32: 39-48, 1989. PubMed: 2911277

Nash TE, et al. Experimental human infections with Giardia lamblia. J. Infect. Dis. 156: 974-984, 1987. PubMed: 3680997

Nash TE, Aggarwal A. Cytotoxicity of monoclonal antibodies to a subset of Giardia isolates. J. Immunol. 136: 2628-2632, 1986. PubMed: 3950421

Nash TE, et al. Antigenic variation of Giardia lamblia in experimental human infections. J. Immunol. 144: 4362-4369, 1990. PubMed: 2341723

Lujan HD, et al. Purification of a variant-specific surface protein of Giardia lamblia and characterization of its metal-binding properties. J. Biol. Chem. 270: 13807-13813, 1995. PubMed: 7775437

Nash TE, et al. Isolate and epitope variability in susceptibility of Giardia lamblia to intestinal proteases. Infect. Immun. 59: 1334-1340, 1991. PubMed: 1706319

Nash TE, et al. Variant specific epitopes of Giardia lamblia. Mol. Biochem. Parasitol. 42: 125-132, 1990. PubMed: 1700296

Nash TE, Keister DB. Differences in excretory-secretory products and surface antigens among 19 isolates of Giardia. J. Infect. Dis. 152: 1166-1171, 1985. PubMed: 4067331

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