VITEK System for Biochemical Identification
The VITEK System is a useful tool to identify different groups of bacteria by a miniaturized biochemical test with specific cards containing 64 fluorescent biochemical tests. Creative Biolabs has 10+ years of experience providing CRO services with a skilled team of scientists who will work with you in developing live biotherapeutic product (LBP). We've built a very mature technology platform.
Principles
VITEK 2 is a growth-based automated microbiology system. It enables rapid identification in hours, compared with days for traditional methods. The system is available in three formats (VITEK 2 Compact, VITEK 2, and VITEK 2 XL), which differ in terms of increased capacity and automation.
Fig.1 Vitek 2 compact instrument and workstation. (Pincus, 2006)
The Procedure of VITEK 2 System
1. Suspension Preparation
A sufficient number of pure culture colonies are transferred using sterile swabs or applicator stick and the microorganisms are suspended in a 12 x 75 mm clear plastic (polystyrene) tube in 3.0 mL sterile saline (0.45% to 0.50% NaCl, pH 4.5 to 7.0). The turbidity is adjusted accordingly and measured using a turbidity meter called the DensiChek.
Fig.2 Suspension turbidities used for card inoculation. (Pincus, 2006)
2. Inoculation
Place the test tube containing microorganism suspension in a special shelf (box). Place the identification card in the adjacent slot and insert the transfer tube into the corresponding suspension tube. After the vacuum is applied, the air is reintroduced to the test stand, and the biological suspension is forced through the transfer tube into microchannels that fill all test wells.
3. Card Sealing and Incubation
All card types are incubated online at 35.5 ± 1.0℃. Test reactions are read every 15 minutes during incubation to measure the turbidity or coloring products of substrate metabolism.
4. Results and Interpretation
The results are interpreted by the VITEK 2 system. The results are interpreted by VITEK 2 system. If a unique recognition pattern is identified, the printed results will indicate a high probability match to a single species. If a unique pattern is not recognized, the system will suggest additional tests to distinguish between two or three closely related organisms or to indicate that the result is an unrecognized organism.
Fig.3 Identification levels. (Pincus, 2006)
Applications
GN cards are designed to automatically identify 135 taxa of the most significant fermented and non-fermented Gram-negative bacilli. GN cards measure carbon source utilization, enzyme activity, and resistance based on established biochemical methods and newly developed substrates. There are 47 biochemical tests and one negative control. Final identification results can be obtained in approximately 10 hours or less.
GP cards are used to automatically identify 115 taxa of the most important non-spore-forming Gram-positive bacteria (mainly cocci). There are 43 biochemical tests, final identification results are available in approximately eight hours or less.
Fig.4 VITEK 2 colorimetric identification card. (Pincus, 2006)
The YST card is used for the automated identification of 49 taxa of the most significant yeasts and yeast-like organisms. There are 46 biochemical tests measuring carbon source utilization, enzyme activity and resistance. Final results will be released about 18 hours later.
The BCL card is used for the automated identification of 38 taxa of the most significant aerobic endospore-forming species of the family Bacillaceae. There are 46 biochemical tests measuring carbon source utilization, enzyme activity, inhibition, and resistance. Final identification results will be released about 14 hours later.
VITEK 2 is an automated microbial identification system. With its colorimetric card and associated hardware and software advances, it delivers highly accurate and repeatable results, providing a state-of-the-art technology platform for phenotypic identification methods. Creative Biolabs applies decades to offer tailored, flexible solutions developing LBP to your needs. If you are interested in our VITEK system, please contact us for more.
Reference
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Pincus, D.H. Microbial identification using the bioMérieux Vitek 2 system. Encyclopedia of Rapid Microbiological Methods. Bethesda, MD: Parenteral Drug Association. 2006: 1-32.
For Research Use Only. Not intended for use in food manufacturing or medical procedures (diagnostics or therapeutics). Do Not Use in Humans.
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