Rapid Automated Microbiology System
The Sy-Lab BacTrac 4300 can analyse liquid and frozen egg products
Egg microbiology testing with no manual plate handling
Rapid microbiological testing system
Automatic detection or enumeration of micro-organisms
Expandable up to measure up to 768 samples
Automated Microbiology
The BacTrac 4300 rapid microbiology system automatically detects or enumerates a wide range of micro-organisms. It holds up to 64 samples in two independently controllable incubator zones. The measurement technique can provide superior sensitivity to microbial metabolites and allow measurements in highly selective media.
Impedance Analysis
Impedance analysis is an automated microbial culture process. The nutrient media and the liquefied product sample are incubated in a measuring cell and the impedance change of the fluid (the alternating current resistance) is monitored using pin electrodes.
Metabolic products that are created when the micro-organisms inside grow constantly changing the resistance, thereby creating an equivalent microbial growth curve. If this exceeds an application dependant threshold value the measuring time recorded until then is set as the detection time and provides information on contamination of the sample.
Measurement positions with finished measurements are assessed and can be immediately reassigned with new cells. The entire measuring cycle is automatic; the results are clearly displayed and can be used for decision making. The software monitors the signal development for all measurements and saves the results in a database for evaluation.
High Sample Volume
It holds up to 64 samples in two independently controllable incubator zones. The measurement technique can provide superior sensitivity to microbial metabolites and allow measurements in highly selective media. Impedance analysis is an automated microbial culture process. The nutrient media and the liquefied product sample are incubated in a measuring cell and the impedance change of the fluid (the alternating current resistance) is monitored using pin electrodes.
Try Before You Buy
The BacTrac 4300 is available for a demonstration or a short term trial.
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Software
- Time already expired from start of the measurement is displayed in the form of a pie chart for every position
- For ongoing measurements the pie chart appears in blue
- As soon as the developing growth signal will reach the threshold, detection time will be recorded. If the color code alert mode has been activated the chart will turn the color to red or yellow depending on the limits defined for the individual position. Negative samples or those with results within specification will be marked green
The database has open access to LIMS, is mirrored database for maximised data safety and features an automated backup option. Data is saved during every measurement cycle and is exportable to many Microsoft Office applications.
Measurement Principle
Microorganisms are detected in real time via the decrease of the impedance in an AC field. Any impedance change caused by the microbial metabolism is detected. In the BacTrac 4300 a proprietary impedance splitting technology is employed. Using this technology the change in the impedance of the electrochemical double layer of the electrode is additionally registered beside the standard impedance signal ( Media Impedance = M- value ).
This so-called electrode impedance (E – value ) requires the use of cells with 4 electrodes and has proven itself for the detection of pathogens as well as for the detection of microbes with low metabolic activity mainly known to be members of the group of gram-positive, heat- tolerant spore formers. The latter are sometimes hardly detected by other automated cultural procedures.
The FoodLab is also available for tests on eggs including L-lactic acid, D-3-hydroxybutyric acid, total acidity, cholesterol, colour and xanthophylls.
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FAQ’s
What are the differences between BacTrac and µ-Trac?
The BacTrac 4300 Microbiological Analyser uses the unique impedance-splitting technology and measures the M-value (media impedance) and E-value (electrode impedance) giving a big variety of possible analyses. Each device contains two individually thermostated incubators for 32 samples each, which can accommodate either disposable or reusable measuring cells. Up to 12 units (768 wells, 24 incubators) can be controlled by one PC. The µ-Trac 4200 is appropriate for smaller laboratories and measures only the M-value. This incubator provides 21 measuring positions suitable for disposable cells only. The µ-Trac is designed to operate with a laptop as a single incubator.
What is Impedance Splitting?
The BacTrac 4300 is registering 2 specific impedance values for each single measurement. These values are displayed as M-value (media impedance) and Evalue (electrode impedance) graphs (displayed as relative changes compared to a starting value) and are based on the Impedance Splitting Method as the measurement principle. This opens the possibility to evaluate the results based on two different signals.
What is the E-value?
The proprietary impedance splitting measurement technology of the BacTrac instruments enables even the use of nutrient media with higher conductivity and therefore significantly broadens the possible applications. In addition to the M-value, changes of the E-value (electrode impedance) will be registered within the impedance splitting concept. For registration of the electrode impedance value the capacitive component of the complex impedance value Z (influence of the electrochemical double layer of the electrode) is of central importance. The technique to measure this electrode impedance value is a special characteristic of the BacTrac measurement technology. The E-value is not significantly influenced by the composition of the growth media and is therefore of central importance when media with high salt content (i.e. addition of salts as selective components for the detection of pathogens) will be used.
Are there standards for impedance technology?
Yes, there are standards for impedance in the U.K.
Does impedance technology comply with the Pharm. Eur.?
After a product-specific validation impedance technology complies with the Pharm. Eur.
How is measurement data saved by the BacTrac?
All data generated by the BacTrac is saved to a database on the hard disk of the PC at the moment the measurement takes place. From this database all measurements can be recalled with the BacEval Software anytime. Additionally results can be printed in colour and exported to other programs like MS Excel(TM).
Is it possible to obtain germ counts with the BacTrac?
Yes. The germ counts are calculated automatically from the detection times of the impedance curves by the BacWin-Software. To do so it is necessary to establish a correlation between BacTrac and plate counts or another counting method. An already available calibration curve can be used under the same conditions after a check against the reference method has been made.
What is the indirect method?
Besides the direct measurement of impedance in the nutrient broth, the detection of carbon dioxide (CO2) produced via the microbial metabolism provides an additional option of recording the activity levels of microorganisms. In this process the impedance change is not detected directly in the nutrient, rather it is the change in impedance of a potassium hydroxide solution caused by the uptake of the CO2 formed that is detected. The indirect impedance measurement represents a rapid and very simple process with pronounced higher sensitivity for the detection of CO2 production. For the detection of yeasts and moulds in particular, whose changes occasionally are hardly registered in the direct method, the indirect method is far superior.
Do all microorganisms form CO2?
All aerobic proliferating micro-organisms produce CO2 as the terminal product of cell metabolism and are therefore suitable for detection with the indirect method.
How much time can be saved using impedance technology compared to traditional plate count method?
Depending on the microorganisms to be analysed the time saved due to use of the BacTrac varies from 12 hours for coliforms to several days for yeasts and moulds, clostridia and beer spoiling bacteria. Furthermore it is not necessary to make dilutions after sample homogenisation and to poor plates and count colonies.
What kind of microorganisms can be detected and what is the detection limit?
Many different kinds of bacteria – like TVC, Enterobacteriaceae, coliforms, Salmonella, Listeria and Clostridia – and yeasts and moulds can be detected with the BacTrac. Basically there have to be living cells in the measuring cell to give an impedance signal. Therefore the detection limit for liquid samples is usually 1 / ml and for solid samples 10 / g. If a pre-enrichment is done the presence in 10 g or 25 g can be tested. In combination with membrane-filter technology e.g. 100 ml of water or lemonade can be analysed.
Specification
Normal Operating Conditions
Nominal Power: 3.9 A {230VAC} or 7.8 A {115VAC} (must be specified at the time of ordering)
Fluctuations of Supply Voltage: +/- 10 % max
Frequency: 50/60 Hz ± 2 %
Ambient Temperature: +15 to +35 °C
Relative Humidity: 15-80 % (non-condensing)
Protection Class: IP 30 (through housing)
Operation of Cooling: Inlet pressure maximum 400 kPa (4 bar)
Dimensions: W 430 mm x D 640 mm x H 380 mm
Weight: 34 kg