What exactly is the fluorescent dye staining?
The fluorescent dye penetrates through the membrane of the dead white blood cells, which are caught up in the milk and binds to the DNA of the cell cores. Once illuminated with light with a wavelength of 470 nm, the bound with the DNA of the cell cores dye emits light with a wavelength of 530 nm. Only the cores of the dead white blood cells are colored.
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Can the unit identify the individual white blood cell types? (Lymphocyte, Macrophage and Neutrophils)?
All the cores of the white blood cells are colored (Lymphocyte, Macrophage and Neutrophils) and they glow with the same color. It is not possible to be differentiated by type. The result from the counting is the total number of somatic cells in 1 ml of milk.
We are working on the possibility to add differentiating of neutrophils in milk.
Does bacteria in the milk have an impact on the SCC test result?
The bacteria are 100 times smaller than the somatic cells and the nuclear material which they contain is 100 times smaller as well. Thus, the emitting of light from the dye, bound with their cores, is negligible in comparison with the light, emitted by the cores of the somatic cells. Such a small light is not reported by the pixels of the CCD sensor and it does not affect the counting.
How many cells can really bind to each of the 16 (or 36) pictures of the sample chambers? You claim 0 to 10,000,000, but it could not be seen where 10,000,000 cells would find the real estate to actually bind in each of the sites...?
There is an answer to this question in the comparative analysis. There’s no need 1 total ml to be scanned in order the cells to be counted with the accuracy required as per the ISO 13366-1:2008. As it is seen from the comparative analysis, in order to receive CV% (coefficient variation) less than 2% for 1 000 000 cells in ml, it is necessary only 4000 cells to be counted out (as per Poisson distribution), while our devices snaps 9000 cells in mode 32 pictures, which means at about 300 cells per position. There’s no problem such number of cells to be bind in the volume, corresponding to 1 position in the chip.
The counter can count sample with many more cells. Very rarely in milk there can be more than 10 000 000 cells.
How does the SCC Tester calculate and report the cells included in the counting (i.e. each site can and often does have a variable count - so how the final count is determined?
There is an answer to this question in the comparative analysis. It could only be added that the results from the counting of each of the 16 or 32 photos (we have an option with 50 photos as well, which correspond to 9 microliters of the scanned milk) are processed statistically in order to exclude the results, which strongly deviate from the average values. Such photos are excluded from the counting. Only correct photos, without defects are being used.
Is the SCC Tester sufficiently robust to bring it around to farms, set it up and do some testing to give the farmers feedback about their cows SCC levels?
The counter is designed for farmers. The last version of the mechanic is not affected by transfer and vibrations as it uses precise ball screw pairs. If the air filters are changed on time, the counter is protected from dust environment. The autofocus is innovative and it has no moving precise parts, it uses a unique liquid lens which also is not affected from vibrations and it cannot be worn out. The tablet is attached by a magnet to the box and can be easily replaced in case of damage. The software is easily upgraded via internet. There is a possibility for a remote servicing through the program for remote control of the counter.
