|Cat. no. Z121||AlbiQuick™ Test Kit||25 tests/kit|
Hardy Diagnostics AlbiQuick™ Test Kit is a rapid test for the identification of Candida albicans by detecting the enzymes beta-galactosaminidase and L-proline aminopeptidase in yeasts.
Hardy Diagnostics AlbiQuick™ Test Kit is based on the ability of yeast species to rapidly hydrolyze the compounds proline-p-nitroanilide (PRO) using the enzyme L-proline aminopeptidase; and 4-methylumbelliferyl-n-acetyl-beta-galactosamine (NAG), using the enzyme beta-galactosaminidase. The test card consists of two separate test circles each containing one of the substrates. When hydrolyzed, the PRO substrate forms a colored end product, and if the NAG substrate is hydrolyzed it produces a fluorescent reaction. Candida albicans produces both enzymes, while other commonly encountered yeasts may be positive for one or the other enzyme but not for both. The total incubation time for AlbiQuick™ is only six minutes.(4,7,8)
Circle A is impregnated with 4-methylumbelliferyl-n-acetyl-beta-galactosamine dissolved in a solvent. Circle B is impregnated with proline-p-nitroanilide dissolved in a solvent. The developers, Reagent A and Reagent B, consist of p-dimethylaminocinnamaldehyde and phosphate buffer, respectively.
STORAGE AND SHELF LIFE
Storage: Upon receipt, store at 2-8ºC. away from direct light. Product should not be used if there are any signs of contamination, deterioration, discoloration, or if the expiration date has passed. Protect reagents from freezing.
Use a culture that is between 24 to 96 hours old to inoculate the AlbiQuick™ Test Card. Isolates may be tested from primary isolation media such as Blood Agar (Cat. no. A10), Chocolate Agar (Cat. no. E14) or may be subcultured onto Sabouraud Dextrose Agar (Cat. no. W70) incubated at room temperature before being tested.
1. Moisten both Circle A and Circle B with one drop of deionized water. Do not oversaturate the test area.
2. Using a sterile loop or applicator stick, remove a heavy, visible paste of yeast cells (2-3 yeast colonies), and smear the paste onto Circle A. Repeat this step for Circle B.
3. Incubate the test card for 5 minutes at room temperature (15-30ºC.).
4. After incubation, add one drop of Reagent B to Circle B. The development of a blue-purple color within 30 seconds (usually immediately) is a positive test for PRO hydrolysis. If no color develops, the test is negative.
5. Add one drop of Reagent A to Circle A. After 30 seconds, examine Circle A under long-wave UV light (366nm). A bright, blue-white fluorescence is a positive test for the hydrolysis of NAG. If no fluorescence is present, the test is negative.
INTERPRETATION OF RESULTS
A positive test for NAG hydrolysis (Circle A) is the appearance of a blue-white fluorescence. No fluorescence is a negative NAG test.
A positive test for PRO hydrolysis (Circle B) is the appearance of a blue-purple color. No change in color is a negative PRO test.
A positive reaction in both circles is a presumptive identification of Candida albicans. Other yeast species will yield negative reactions in one or both circles.
If the culture is mixed, either with other bacteria or with other yeasts, the test will not give reliable results.
If the yeast culture used is less than 24 hours old or if a small inoculum is used, false results may occur.
The AlbiQuick™ test provides only a presumptive identification of Candida albicans. Other serological and biochemical tests may be performed for a complete identification. Consult listed references for more information.(1,5)
Some strains of Candida parapsilosis may be positive for both NAG and PRO hydrolysis.
MATERIALS REQUIRED BUT NOT PROVIDED
Standard microbiological supplies and equipment such as loops, long-wave UV lamp, other culture media, microscopes, incinerators, incubators, etc., as well as other biochemical and serological reagents, are not provided.
|Test Organisms||Inoculation Method*||Incubation||Results|
(Circle A) positive:
blue-white fluorescence under UV light
(Circle B) positive:
blue-purple color change
(Circle A) negative:
no fluorescence under UV light
(Circle B) negative:
no color change
User Quality Control
- The two circles on the AlbiQuick™ Test Card should appear slightly off-white in color.
- Reagent A should be clear, and blue in color.
- Reagent B should appear clear, and straw-yellow to light pink in color.
Candida albicans (ATCC® 10231) smear showing NAG hydrolysis on AlbiQuick™ Test Card (Cat no. Z121) shown under UV light. Incubated aerobically for 5 minutes at room temperature.
Candida albicans (ATCC® 10231) smear showing PRO hydrolysis on AlbiQuick™ Test Card (Cat no. Z121) shown under ambient light. Incubated aerobically for 5 minutes at room temperature.
1. Anderson, N.L., et al. Cumitech 3B; Quality Systems in the Clinical Microbiology Laboratory, Coordinating ed., A.S. Weissfeld. American Society for Microbiology, Washington, D.C.
2. Versalovic, J., et al. Manual of Clinical Microbiology. American Society for Microbiology, Washington, D.C.
3. Tille, P.M., et al. Bailey and Scott's Diagnostic Microbiology, C.V. Mosby Company, St. Louis, MO.
4. Dealler, S.F. J. Clin. Microbiology; 29:1081-1082.
5. Isenberg, H.D. Clinical Microbiology Procedures Handbook, Vol. I, II & III. American Society for Microbiology, Washington, D.C.
6. Koneman, E.W., et al. Color Atlas and Textbook of Diagnostic Microbiology. J.B. Lippincott Company, Philadelphia, PA.
7. Perry, J.L., et al. J. Clin. Microbiology; 25:2424-2425.
8. Smitka, C.M., et al. J. Clinical Microbiology; 27:203-206.
ATCC is a registered trademark of the American Type Culture Collection.