The EU-RL certification of the BactoScan FC+ has been performed in accordance with EN ISO/DIS 16140-2:2013, the EURL MMP criteria and the Microval Rules and Certification Scheme. In short, this validates the BactoScan FC+ as a method which is at least equivalent to the reference method based on plate counting of bacteria colony forming units (EN-ISO 4833-1:2013, parts 1 and 2).
Approved in the USA and Europe
FOSS was the first to develop the rapid bacteria count method in the early 1980’s. The EU-RL certification adds to an existing FDA/NCIMS certification as a rapid electronic counting method in the USA. It is the only rapid method for bacteria count in raw milk to have both approvals.
The BactoScan FC+ has become the industrial standard for counting total bacteria in many countries all over the world. In contrast to the reference method, the rapid BactoScan FC+ test measures individual bacteria cells using a technique called flow cytometry. With the technique, a suspension of cells is stained and forced through a capillary tube, which is illuminated in front of a microscope objective. Every passing cell is then registered by photo electronics attached to the microscope.
An individual result is delivered in just nine minutes compared to the two to three days it takes with plate counting. The BactoScan FC+ can test up to 200 samples in an hour.
The importance of rapid tests
The rapid results are important because catching hygiene breaches in raw milk early is essential for minimizing the impact on milk quality. Although pasteurisation will kill the majority of bacteria, their metabolites may cause off flavours and enzymes continue their activities resulting in product defects and reduction of shelf life.
With the traditional plate count method, hygienic problems on the farm may go undetected for days, making corrective actions more difficult and production losses larger than necessary. With the BactoScan test, farmers can be advised about possible problems the same day as the sample is drawn allowing timely correction for leaks, insufficient cleaning or cooling in the milking system, or health problems in the herd.
Superior accuracy through individual bacteria count
Because the BactoScan™ FC+ counts all bacteria as single cells and not clusters it gives a uniform high performance with accuracy, repeatability and reproducibility of results. Unlike methods such as the plate counting method, BactoScan FC+ cannot be influenced by the operator and it can analyse raw milk samples directly without prior heating or dilution, which can affect precision.
Accuracy: Typical Sy,x < 0.25 log units in the entire measuring range
Reference method: Standard Plate Count (IDFStandard 100B: 1991).
How it works
BactoScan™ FC+ is based on flowcytometry technology that enables precise and instant milk bacteria analysis. Flowcytometry is a technique that counts and characterises particles and cells.
The principle behind flowcytometry is quite simple: A suspension of cells is stained and forced through a capillary tube, which is illuminated in front of a microscope objective. Every passing cell is then registered by photo electronics attached to the microscope.
Sample in flow cell
The BactoScan™ FC+ counts the bacteria
1. By incubating the milk with a unique incubation liquid and by employing mechanical treatment, all components in the milk are broken down except for the bacteria. The bacteria clusters are also separated into single bacteria
2. During the incubation period, the bacteria are stained with a DNA-specific staining medium
3. At the measuring point, the sample material is exposed to a light beam from a laser source, forcing the stained bacteria to emit red light - one light pulse for every bacteria passing the beam
4. A very precise syringe is used to pass the whole sample through a flow cell, presenting the bacteria one by one
5. The electronics count the pulses and display them in a pulse height analysis diagram on the PC monitor.
