Giardia intestinalis (Lambl) Alexeieff (ATCC® 50581)

Strain Designations: GS clone H7  /  Depositor: TE Nash  /  Biosafety Level: 2

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Strain Designations GS clone H7
Enteric Research
Food and waterborne pathogen research
Biosafety Level 2
Product Format frozen
Type Strain no
Genome Sequenced Strain


Cysteine-rich variant surface proteins
Frequency of variant antigens
Antigenic variation
Purification of variant-specific surface protein
Epitope variability in susceptibility to proteases
Metabolism of cysteine
Association of variant surface antigens with thick cell coat
Differentiation induced by cholesterol starvation
Variant specific epitopes
Control of infections in mice
Genome sequencing strain
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 2695.

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

Name of Depositor TE Nash
Special Collection NCRR Contract

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. Frequency of variant antigens in Giardia lamblia. Exp. Parasitol. 71: 415-421, 1990. PubMed: 1699782

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

Lujan HD, Nash TE. The uptake and metabolism of cysteine by Giardia lamblia trophozoites. J. Eukaryot. Microbiol. 41: 169-175, 1994. PubMed: 8167619

Pimenta PF, et al. Variant surface antigens of Giardia lamblia are associated with the presence of a thick cell coat: Thin section and label fracture immunocytochemistry survey. Infect. Immun. 59: 3989-3996, 1991. PubMed: 1937758

Lujan HD, et al. Cholesterol starvation induces differentiation of the intestinal parasite Giardia lamblia. Proc. Natl. Acad. Sci. USA 93: 7628-7633, 1996. PubMed: 8755526

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

Singer SM, Nash TE. T-cell-dependent control of acute Giardia lamblia infections in mice. Infect. Immun. 68: 170-175, 2000. PubMed: 10603384

Langford TD, et al. Central importance of immunoglobulin A in host defense against Giardia spp. Infect. Immun. 70: 11-18, 2002. PubMed: 11748158

Marti M, et al. Conformationally correct expression of membrane-anchored Toxoplasma gondii SAG1 in the primitive protozoan Giardia duodenalis. Infect. Immun. 70: 1014-1016, 2002. PubMed: 11796643

Nash T, Rice WG. Efficacies of zinc-finger-active drugs against Giardia lamblia. Antimicrob. Agents Chemother. 42: 1488-1492, 1998. PubMed: 9624499

Elmendorf HG, et al. The abundance of sterile transcripts in Giardia lamblia. Nucleic Acids Res. 29: 4674-4683, 2001. PubMed: 11713317

Touz MC, et al. The activity of a developmentally regulated cysteine proteinase is required for cyst wall formation in the primitive eukaryote Giardia lamblia. J. Biol. Chem. 277: 8474-8481, 2002. PubMed: 11773053

Singer SM, et al. Biological selection of variant-specific surface proteins in Giardia lamblia. J. Infect. Dis. 183: 119-124, 2001. PubMed: 11087204

Murtagh JJ Jr., et al. Guanine nucleotide-binding proteins in the intestinal parasite Giardia lamblia. Isolation of a gene encoding an approximately 20-kDa ADP-ribosylation factor. J. Biol. Chem. 267: 9654-9662, 1992. PubMed: 1577802

Gottstein B, et al. Human cellular immune response to Giardia lamblia. Infection 19: 421-426, 1991. PubMed: 1816113

Gottstein B, Nash TE. Antigenic variation in Giardia lamblia: infection of congenitally athymic nude and scid mice. Parasite Immunol. 13: 649-659, 1991. PubMed: 1725820

Gottstein B, et al. Antigenic variation in Giardia lamblia: cellular and humoral immune response in a mouse model. Parasite Immunol. 12: 659-673, 1990. PubMed: 1707508

Cross References

Nucleotide (GenBank) : ACGJ01000000 Giardia intestinalis ATCC 50581 strain GS/M clone H7, whole genome shotgun sequencing project.

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