Membrane Filter-Deoxyribonucleic Acid Method of Somatic Cell Counting: Collaborative Study

1980 ◽  
Vol 63 (2) ◽  
pp. 211-218
Author(s):  
Robert D Bremel ◽  
◽  
T Bredar ◽  
R Case ◽  
B Cathardi ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Somatic Cell ◽  
Deoxyribonucleic Acid ◽  
Membrane Filter ◽  
Collaborative Study ◽  
Cell Counting ◽  
Color Development ◽  
Cell Counts ◽  
Chemical Determination ◽  
Acid Test

Abstract In the membrane filter-deoxyribonucleic acid test, somatic cells are trapped on a special filter. A chemical determination of the DNA of the trapped material gives an estimate of the number of cells. The MF-DNA was evaluated and compared with the direct microscopic somatic cell counts (DMSCCs) in 10 laboratories. Cell levels in the 10 bulk milk samples analyzed ranged from 380,000 to 1,700,000/mL. Regression analysis gave a relation of 0.181 absorbance at 490 nm, when 2.5 mL of milk was analyzed and 5.0 mL reagent was used for color development. The 95% confidence limits on the slope were 0.158-0.204. Analysis of variance showed that both procedures had significant (P<0.001) systematic errors, but that only the DMSCC method showed a significant laboratory X sample interaction (P<0.001). The repeatability standard deviation of the MF-DNA procedure was 117,000 cells/mL (14%), and the reproducibility standard deviation was 198,000/ mL (23%). This compared favorably with the DMSCC method which had a repeatability of I62,000/mL (19%) and a reproducibility of 287,000/mL (34%). The error of the MF-DNA was constant at all cell counts, whereas there was a tendency for the error to increase in the DMSCC method at high cell counts. This method has been adopted as official first action.

Collaborative Study of an Automated Optical Somatic Cell Counting Method for Raw Milk

1973 ◽  
Vol 56 (4) ◽  
pp. 950-956
Author(s):  
Wesley N Kelley
Keyword(s):  
Standard Deviation ◽  
Somatic Cell ◽  
Collaborative Study ◽  
Sampling Rate ◽  
Raw Milk ◽  
Cell Counting ◽  
Counting Method ◽  
Milk Samples ◽  
Comparison Of Results ◽  
Statistical Results

Abstract A collaborative study was conducted to compare tbe automated optical somatic cell counting method (OSCC) with the direct microscopic somatic cell counting method (DMSCC) for raw milk. Samples were prefixed with formaldehyde and introduced into an Auto-Analyzer system. Dilution, clarification, and cell counting were performed automatically. Eight collaborators participated in the study, analyzing 48 samples in duplicate, using 2 different sampling rates. The results were compared with DMSCC counts reported by 3 different analysts. Statistical results show that the standard deviation for the DMSCC method was 0.1086 and for the OSCC method, at a sampling rate of 30/hr, 0.0911. From comparison of results it appears that the OSCC method is as accurate as, and more precise than, the DMSCC method. The faster sampling rate of the OSCC method (60/hr) has some effect on precision but little effect on accuracy. The method has been adopted as official first action.

Collaborative Study to Determine Effects of Milk Composition on Somatic Cell Counts

1990 ◽  
Vol 53 (1) ◽  
pp. 67-71 ◽  
Author(s):  
J. S. HOGAN ◽  
K. LARRY SMITH ◽  
D. A. TODHUNTER ◽  
P. S. SCHOENBERGER
Keyword(s):  
Somatic Cell ◽  
Protein Content ◽  
Collaborative Study ◽  
Fat Content ◽  
Cell Counting ◽  
Bulk Tank Milk ◽  
Somatic Cell Counts ◽  
Milk Samples ◽  
Cell Counts ◽  
Bulk Tank

Quarter, composite, and bulk tank milk samples were analyzed in a three laboratory collaborative study to determine the relationship of milk fat and protein content with milk somatic cell counts. Milk somatic cell counts were determined by two Coulter counters, a Fossomatic counter, and by direct microscopic somatic cell counting. In general, variability among somatic cell counts measured by different procedures was not related to protein or fat content of milk. The greatest percentage of variation between counts that could be explained by fat content of milk was 20.2% between a Coulter and direct microscopic somatic cell counts. The greatest percentage of variation between counts that could be explained by protein content of samples was 12.9% between a Coulter and Fossomatic counts. Breed of cow from which samples were collected also had little influence on differences among milk somatic cell counts. Differences among milk somatic cell counts due to counting methods did vary among quarter, composite, and bulk tank milk samples.

Somatic Cell Reference Samples for Calibration of Milk Somatic Cell Counting Methods

1984 ◽  
Vol 47 (9) ◽  
pp. 694-696 ◽  
Author(s):  
T. J. LINTNER ◽  
C. W. HEALD ◽  
R. J. EBERHART
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Potassium Dichromate ◽  
Collaborative Study ◽  
Skim Milk ◽  
Cell Counting ◽  
Cell Counts ◽  
Counting Methods ◽  
Raw Bulk Milk

Somatic cell count samples (SCCS) for use in calibration of milk somatic cell counting methods were prepared from raw bulk milk preserved with potassium dichromate. Somatic cells were separated by centrifugation, then appropriate cell dilutions were prepared in the dichromate-preserved skim milk. Somatic cell counts from SCCS stored at 4°C were stable over a 23-wk period. No bacterial contamination was detected in these samples. In a collaborative study among eight laboratories, SCCS were not affected by usual conditions by shipping. The SCCS can be used as reference standards for the direct microscopic somatic cell count and the Fossomatic and Coulter Counter somatic cell counting methods.

Collaborative Study of the Coulter Counter-Chemical Method for Counting Somatic Cells in Raw Milk1

1977 ◽  
Vol 40 (7) ◽  
pp. 456-458 ◽  
Author(s):  
R. E. GINN ◽  
D. R. THOMPSON ◽  
V. S. PACKARD
Keyword(s):  
Standard Deviation ◽  
Somatic Cell ◽  
Somatic Cell Count ◽  
Chemical Method ◽  
Collaborative Study ◽  
Somatic Cells ◽  
Cell Counting ◽  
Milk Samples ◽  
Counting Procedure ◽  
Electronic Counting

Variation between laboratories for Electronic Somatic Cell Counting by the chemical method (ESCC) was evaluated by a collaborative study. Eight laboratories counted somatic cells in 12 milk samples (six replicated samples) by the ESCC method. The somatic cell count for the same milk samples was also evaluated by the Direct Microscopic Somatic Cell Counting procedure (DMSCC) as a comparison for the level of error. The standard deviation of the variation of logarithms of ESCC counts between laboratories was 0.04368. The standard deviation for the variation of logarithms of DMSCC counts between technicians was 0.08617. The corresponding value for the DMSCC analysis of the last set of federal split milk samples was 0.141. An earlier study of electronic counting by the centrifuge method showed a standard deviation of 0.0711.

Determination of somatic cells in milk by solid phase cytometry

2001 ◽  
Vol 68 (1) ◽  
pp. 9-14 ◽  
Author(s):  
EVA D'HAESE ◽  
HANS J. NELIS ◽  
WIM REYBROECK
Keyword(s):  
Somatic Cell ◽  
Laser Scanning ◽  
Solid Phase ◽  
Membrane Filter ◽  
Method Comparison ◽  
Cell Counting ◽  
Epifluorescence Microscopy ◽  
Cell Counts ◽  
Electronic Method ◽  
Direct Epifluorescent Filter Technique

The somatic cell count of milk is routinely determined by the fluoro-opto-electronic method and sometimes by the direct epifluorescent filter technique (DEFT). This paper investigates the potential of solid phase cytometry (SPC), a novel technique combining aspects of both the fluoro-opto-electronic method and epifluorescence microscopy for somatic cell counting. In SPC, cells are retained on a membrane filter, fluorescently labelled and automatically detected on the entire membrane filter by means of a laser scanning instrument (ChemScan). Fluorescent spots can be visually inspected by an epifluorescence microscope with a computer-driven moving stage. The performance of SPC was compared with that of the fluoro-opto-electronic method using a Fossomatic 360 instrument for 68 milk samples with varying somatic cell counts (103–106/ml). The sample throughput and repeatability of SPC were inferior to those of the Fossomatic method and statistical analysis of the method comparison data using the approach of J. M. Bland & D. G. Altman (The Lancet 1986 February 8 pp 307–310) revealed a poor comparability between the two methods. Moreover, problems of milk filterability and the interference of fluorescent particles presently hamper the routine application of SPC. Nevertheless, this method represents the first example of the application of SPC to milk.

Fossomatic Method of Somatic Cell Counting in Milk: Collaborative Study

1978 ◽  
Vol 61 (4) ◽  
pp. 779-784
Author(s):  
Richard D Mochrie ◽  
Robert J Monroe
Keyword(s):  
Somatic Cell ◽  
Collaborative Study ◽  
Cell Counting ◽  
Th Cells ◽  
Linear Coefficient ◽  
Fresh Milk ◽  
Cell Counts ◽  
Local Standard ◽  
Fully Automatic ◽  
Cell Counter

Abstract Fossomatic, a fully automatic, fluoro-optoelectronic somatic cell counter, was evaluated in 6 laboratories. One set of 6 duplicate milk samples, fresh and preserved, was read with instruments as routinely calibrated to each laboratory’s direct microscopic somatic cell counts (DMSCCs), i.e., local standard. A second set was read after standardizing the instrument to a 3-sample common standard (DMSCC) shipped to each collaborator. Cell levels of the unknowns ranged from 371 to 2301 thousand (th)/ml by DMSCC, with an s per sample of 14.8% and s of a level mean of 1.8%. Fossomatic values averaged 1014 compared to 1031 th cells/ml by DMSCC, had homogeneous variance for duplicates within laboratories (s = 4.0%), and had an error per observation of 6.2%. The linear coefficient of 0.9966±0.0039 (for fresh milk and common standard) for the Fossomatic values regressed on DMSCC gave an excellent and unbiased estimate of the cell concentration in a milk sample. A small bias was evident in only 5 of 24 linear regressions (fresh or preserved within each standard) where slopes differed significantly from 1. All 5 were on values derived from a local standard with maximum biases of +18% and —28% (at a 1 million level). Preserved milk had slightly lower (P < 0.01) cell concentrations than fresh milk but only by 3.6% at 1 million. Although condition X level was significant (P < 0.01), the 6 cell levels differed by a magnitude of only 27— 45 th cells/ml. Between-laboratory variation (the component was 4.6%) and laboratory X level interaction were both significant, but their contributions to error were small. The spread in laboratories at any cell level was about 12% and the error of estimate for a sample sent to 2 laboratories was 6.8%. Although interactions were significant with this precise method, they were not of such a magnitude as to invalidate cell count estimates in practice. The Fossomatic method has been adopted as official first action.

Improved Automated Optical Somatic Cell Counting Method for Raw Milk: Collaborative Study

1978 ◽  
Vol 61 (6) ◽  
pp. 1328-1334
Author(s):  
Wesley N Kelley
Keyword(s):  
Standard Deviation ◽  
Somatic Cell ◽  
Collaborative Study ◽  
Sampling Rate ◽  
Raw Milk ◽  
Cell Counting ◽  
Counting Method ◽  
Milk Samples ◽  
Counting Procedure ◽  
Statistical Results

Abstract A collaborative study was conducted to compare the improved automated optical somatic cell counting procedure (OSCC II) with the direct microscopic somatic cell counting method (DMSCC) in raw milk. Samples were prefixed with formaldehyde and introduced into an Auto- Analyzer system. Dilution, clarification, and cell counting were performed automatically. Five collaborators participated in the study; they analyzed 48 samples in duplicate, using 2 different sampling rates. The results were compared with DMSCC counts reported by 3 different analysts. Statistical results show that the standard deviation for the DMSCC method is 0.0825 and for the OSCC II, at a sampling rate of 80/hr, 0.0434. When results are compared, the OSCC II procedure is as accurate as, and is significantly more precise than, the DMSCC method. The faster sampling rate of the OSCC II at 120/hr has some effect on precision but little effect on accuracy. The method has been adopted as official first action.

Differentiation and Enumeration of Somatic Cells in Goat Milk

1982 ◽  
Vol 45 (5) ◽  
pp. 435-439 ◽  
Author(s):  
A. M. DULIN ◽  
M. J. PAAPE ◽  
W. P. WERGIN
Keyword(s):  
Somatic Cell ◽  
Deoxyribonucleic Acid ◽  
Membrane Filter ◽  
Somatic Cells ◽  
Goat Milk ◽  
Cow Milk ◽  
Methyl Green ◽  
Somatic Cell Counts ◽  
Cell Counts ◽  
Significant Difference

Non-leukocytic cell-like particles commonly observed in goat milk were examined ultrastructurally and cytochemically. Transmission electron microscopy indicated that these particles were generally membrane-bound and anucleate. They contained granular material in the dilated cisternae of the endoplasmic reticulum and homogeneous electron translucent inclusions that resembled lipid. Histochemical and fluorescent staining indicated that the particles contained large amounts of protein, some lipid, but no deoxyribonucleic acid. Several methods routinely used for estimating somatic cell counts in cow milk were compared to determine which one would give accurate estimates of somatic cell counts in goat milk. No significant difference was found (P> .05) among methods which specifically measure deoxyribonucleic acid. These included Membrane Filter-DNA, direct microscopic somatic cell counts using Pyron in Y-methyl green stain, and Fossomatic cell counts. Results of the Wisconsin Mastitis Test did not differ significantly from Fossomatic cell counts. Because Coulter electronic counts and direct microscopic somatic cell counts using Levowitz-Weber stain could not differentiate between the cell-like particles and the actual leukocytes, these methods resulted in elevated cell counts that were highly variable. Results indicate that only those counting methods that are specific for deoxyribonucleic acid can distinguish cell-like particles from somatic cells, and thereby give reliable estimates of somatic cell numbers in goat milk.

scholarly journals Extensive Countrywide Field Investigation of Somatic Cell Counts and Total Bacterial Counts in Bulk-Tank Raw Milk in Sheep Flocks in Greece

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 268
Author(s):  
Daphne T. Lianou ◽  
Charalambia K. Michael ◽  
Natalia G. C. Vasileiou ◽  
Efthymia Petinaki ◽  
Peter J. Cripps ◽  
...  
Keyword(s):  
Somatic Cell ◽  
Geometric Mean ◽  
Cell Counting ◽  
Lactation Period ◽  
Mechanical Ventilators ◽  
Bulk Tank Milk ◽  
Bacterial Counts ◽  
Somatic Cell Counts ◽  
Cell Counts ◽  
Bulk Tank

Objectives were to investigate somatic cell counts (SCC) and total bacterial counts (TBC) in the raw bulk-tank milk of sheep flocks in Greece, to study factors potentially influencing increased SCC and TBC in the bulk-tank milk of sheep and to evaluate possible associations of SCC and TBC with milk content. Throughout Greece, 325 dairy sheep flocks were visited for collection of milk sampling for somatic cell counting, microbiological examination and composition measurement. Geometric mean SCC were 0.488 × 106 cells mL−1; geometric mean TBC were 398 × 103 cfu mL−1; 228 staphylococcal isolates were recovered form 206 flocks (63.4%). Multivariable analyses revealed annual incidence risk of clinical mastitis, age of the farmer and month into lactation period (among 53 variables) to be significant for SCC > 1.0 × 106 cells mL−1 and month into lactation period at sampling and availability of mechanical ventilators (among 58 variables) to be significant for TBC > 1500 × 103 cfu mL−1. Negative correlation of SCC with fat, total protein and lactose and positive correlation of SCC with added water were found. With SCC > 1.0 × 106 cells mL−1, significant reduction of protein content (2%) was observed, whilst in flocks with SCC > 1.5 × 106 cells mL−1, significantly lower annual milk production per ewe (42.9%) was recorded.

Optical Somatic Cell Counting and Total Protein Analysis in a Dairy Herd Improvement Program1

1977 ◽  
Vol 40 (10) ◽  
pp. 671-675 ◽  
Author(s):  
N. WANG ◽  
G. H. RICHARDSON
Keyword(s):  
Somatic Cell ◽  
Total Protein ◽  
Potassium Dichromate ◽  
Somatic Cells ◽  
Dairy Herd ◽  
Cell Counting ◽  
Ambient Conditions ◽  
Fresh Milk ◽  
Cell Counts ◽  
Cheese Industry

Milk sample preparation for Optical Somatic Cell Counter II operation was simplified by using a diluter to add fixative, mix, and dilute samples. Potassium dichromate preservative tablets produced a mean increase of 7,000 in somatic cell counts in fresh milk. Samples held at 20–23 C beyond 2 days or at 4–7 C beyond 4 days showed a reduction in somatic cell count. The mean somatic cells in 3 Holstein herds tested over a 6-month period was 3.8 × 105/ml. A 22-month survey of 52.6 thousand Utah Dairy Herd Improvement samples which were shipped under ambient conditions and then held at 5 C until tested, indicated 75% below 400,000 and 2.7% above 1.6 million somatic cells/ml. Casein, noncasein protein, total protein, fat and milk weight data were also obtained on the three herds. Multiple correlations were obtained. The best correlations suggested that testing for total protein and somatic cells in a central laboratory would estimate casein and noncasein protein. Such tests are most valuable for the cheese industry.

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