Uses and Limitations of the XTT Assay in Studies of Candida Growth and Metabolism

ABSTRACT Colorimetric tetrazolium assays are used increasingly in studies of fungi, often in the absence of standardization or correlation with other methods. We examined species- and strain-related tetrazolium metabolism in Candida albicans and Candida parapsilosis by using XTT {2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide} and WST-8 [2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulphonyl)-2H-tetrazolium] and found marked variations. Also, significant signal was often missed in the absence of dimethyl sulfoxide extraction.

[1]  H. Lillehoj,et al.  Lymphocyte Proliferation Response During Eimeria tenella Infection Assessed by a New, Reliable, Nonradioactive Colorimetric Assay , 2002, Avian diseases.

[2]  L. J. Douglas,et al.  Biofilm formation by Candida species on the surface of catheter materials in vitro , 1994, Infection and immunity.

[3]  F. P. Altman.  Tetrazolium salts and formazans. , 1976, Progress in histochemistry and cytochemistry.

[4]  S. Levitz,et al.  A rapid colorimetric assay of fungal viability with the tetrazolium salt MTT. , 1985, The Journal of infectious diseases.

[5]  M. Ghannoum,et al.  Antifungal Susceptibility of Candida Biofilms: Unique Efficacy of Amphotericin B Lipid Formulations and Echinocandins , 2002, Antimicrobial Agents and Chemotherapy.

[6]  T. Meshulam,et al.  A simplified new assay for assessment of fungal cell damage with the tetrazolium dye, (2,3)-bis-(2-methoxy-4-nitro-5-sulphenyl)-(2H)-tetrazolium-5-carboxanil ide (XTT). , 1995, The Journal of infectious diseases.

[7]  N. Roehm,et al.  An improved colorimetric assay for cell proliferation and viability utilizing the tetrazolium salt XTT. , 1991, Journal of immunological methods.

[8]  M. Ghannoum,et al.  Comparison of Biofilms Formed by Candidaalbicans and Candidaparapsilosis on Bioprosthetic Surfaces , 2002, Infection and Immunity.

[9]  S. Hawser.  Adhesion of different Candida spp. to plastic: XTT formazan determinations. , 1996, Journal of medical and veterinary mycology : bi-monthly publication of the International Society for Human and Animal Mycology.

[10]  M. Ghannoum,et al.  Antifungal Resistance of Candidal Biofilms Formed on Denture Acrylic in vitro , 2001, Journal of dental research.

[11]  D. Scudiero,et al.  The synthesis of XTT: a new tetrazolium reagent that is bioreducible to a water-soluble formazan , 1988 .

[12]  Mahmoud A. Ghannoum,et al.  Biofilm Formation by the Fungal PathogenCandida albicans: Development, Architecture, and Drug Resistance , 2001, Journal of bacteriology.

[13]  S. Hawser,et al.  Binding of Candida albicans to Immobilized Amino Acids and Bovine Serum Albumin , 1998, Infection and Immunity.

[14]  T. Mosmann.  Rapid colorimetric assay for cellular growth and survival: application to proliferation and cytotoxicity assays. , 1983, Journal of immunological methods.

[15]  M. Ghannoum,et al.  Comparison of a 2,3-Bis(2-Methoxy-4-Nitro-5-Sulfophenyl)-5-[(Phenylamino)Carbonyl]-2H-Tetrazolium Hydroxide (XTT) Colorimetric Method with the Standardized National Committee for Clinical Laboratory Standards Method of Testing Clinical Yeast Isolates for Susceptibility to Antifungal Agents , 1998, Journal of Clinical Microbiology.