Collaborative Study of Alkaline Phosphatase Activity in Filter Paper Disks Impregnated with Skim Milk: Positive Control Sample

1982 ◽  
Vol 45 (2) ◽  
pp. 112-114 ◽  
Author(s):  
G. K. MURTHY ◽  
J. T. PEELER
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Filter Paper ◽  
Room Temperature ◽  
Collaborative Study ◽  
Control Sample ◽  
Skim Milk ◽  
Positive Control ◽  
Colorimetric Test

The rapid colorimetric test was used in a collaborative study to determine alkaline phosphatase activity in filter paper disks impregnated with skim milk then dried and stored for several months at room temperature. Five samples of filter paper disks (0 to 6 μg phenol/disk) in duplicate were sent to six collaborators for analysis. Computations of analytical and analyst errors showed variations of 22.2 to 48.8%. Most of the variations were due to differences among analysts, but some were partly due to differences in the slopes of the calibration curves (a = 0.05 level) they prepared at the time of analysis. Collaborator's performance was evaluated by comparing % correct results that were positive (negative) with the expected results. About 95% of the samples were correctly analyzed.

Preparation of a Positive Control Sample for Use in the Routine Analysis of Milk and Milk Products for Alkaline Phosphatase

1982 ◽  
Vol 45 (2) ◽  
pp. 108-111 ◽  
Author(s):  
G. K. MURTHY
Keyword(s):  
Alkaline Phosphatase ◽  
Filter Paper ◽  
Room Temperature ◽  
Control Sample ◽  
Skim Milk ◽  
Positive Control ◽  
Routine Analysis ◽  
Milk Products ◽  
Continuous Vacuum ◽  
Control Samples

A method was developed for preparing filter paper impregnated with raw skim milk to serve as positive control samples during the routine analysis of milk and milk products for alkaline phosphatase. Whatman No. 40 filter paper circles (12.5-cm diameter) were dipped in raw skim milk standardized to known concentrations of alkaline phosphatase. Excess milk was removed by draining and blotting between folds of blotting paper. The filter papers were dried over silica gel in a desiccator under continuous vacuum for 5 to 6 days. Disks measuring 0.64-cm were punched out of the dried filter paper circles and stored in screw-cap test tubes at room temperature in the dark until use. The relationship between the alkaline phosphatase contents of milk and the filter paper disks was linearly correlated and characterized by the equation: [Edisk] = 0.0071 × [Emilk] + 0.41, and r = 0.98. Reproducibility of preparing impregnated filter paper circles showed coefficients of variation of 3.3 to 15.7%. Statistical analysis of the data relating alkaline phosphatase activity with days of storage by analysis of variance and regression analysis indicated significant differences in the slope of the regression lines at the a = 0.05 level. At the end of 406 to 599 days of storage, the estimated decrease in [Edisk] for significant samples ranged from 25.6 to 38.9%, with an average ± SD of 33.0 ± 4.4%. Data do show, however, that filter paper disks can be prepared to contain known concentrations of alkaline phosphatase and stored at room temperature for several months for use as positive control samples.

Enzyme-Histochemical Determination of Human Bone Growth Activity in Postmortem Material

1973 ◽  
Vol 52 (6) ◽  
pp. 1293-1296 ◽  
Author(s):  
Inger Kjær ◽  
Uwe Prydsoe
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Incubation Medium ◽  
Room Temperature ◽  
Bone Growth ◽  
Autopsy Material ◽  
Growth Activity ◽  
Enzyme Alkaline Phosphatase

Autopsy material from calvarian bones and sutures of two children, was used to determine growth activity by measuring enzyme alkaline Phosphatase activity. In the extremely active periosteum of the 2-day-old boy, differences in growth activity could be demonstrated by reduction of the temperature of the incubation medium from room temperature to 4 C.

UTILIZATION OF PHENOLPHTHALEIN MONOPHOSPHATE TO TO DETERMINE THE PHOSPHATASE ACTIVITY OF MILK1

1972 ◽  
Vol 35 (7) ◽  
pp. 405-409 ◽  
Author(s):  
Dick H. Kleyn
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Rapid Method ◽  
Alkaline Phosphatase Activity ◽  
Collaborative Study ◽  
Correlation Coefficients ◽  
Raw Milk ◽  
New Method ◽  
Chocolate Milk ◽  
Positive Correlations

The properties of alkaline phosphatase as it exists in milk are considered. The more common methods of measuring alkaline phosphatase activity in milk are briefly reviewed, especially those employing substrates possessing “built-in” indicators which produce a chromogen directly upon hydrolysis. The visual procedure employing phenolphthalein monophosphate as the substrate is given. The sensitivity of this method is shown to be far greater than that of the Scharer I (Rapid) method. Results of an AOAC Collaborative study demonstrated that the method yields results that are as precise and either as accurate as or more accurate than those obtained by the Scharer I (Rapid) method. The quantitative spectrophotometric procedure employing the above substrate is presented. Comparison of this method with the Scharer modified spectrophotometric method on milk revealed correlation coefficients (Scharer method: 0.998 and modified new method 0.991) showing very little difference in the positive correlations of absorbance values and % raw milk. For chocolate milk, the values were 0.990 and 0.990 for the respective methods. Collaborative study of this method has demonstrated that the random error of the modified new method is almost twice that of the Scharer technique while the systematic error is only about one-fourth of the latter method.

Collaborative Study of Rapid Methods for Alkaline Phosphatase in Milk and Cream

1979 ◽  
Vol 42 (10) ◽  
pp. 800-803 ◽  
Author(s):  
G. K. MURTHY ◽  
J. T. PEELER
Keyword(s):  
Alkaline Phosphatase ◽  
Limit Of Detection ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Skim Milk ◽  
Rapid Test ◽  
Raw Milk ◽  
Colorimetric Test ◽  
Photoelectric Colorimeter

Determination of alkaline phosphatase activity in milk and cream by the modified Scharer rapid test with use of photoelectric colorimeter for measuring absorbance was collaboratively studied. Milk samples (skim milk. milk and cream) with and without added raw milk were sent to 12 collaborators to be tested by (a) the modified Scharer rapid test using commercial standards and phenol standards for comparing colors, (b) the rapid colorimetric test and (c) the Rutgers method. The latter method was used for comparison only. In the modified Scharer rapid test, based on the category of standards, 73.3% of the samples using the commercial standards and 71.6% of the samples using phenol standards were correctly diagnosed. When the scoring was based on positive or negative, 98.4 and 92.6% of the samples were correctly diagnosed. Results with the phenol standards were significantly lower than those observed with the commercial standards. There were no false-positive results, as all incorrect readings were below limit of detection. Most of the errors occurred when the expected value was 1.0 μg phenol/ml. Results were 100% correct for the Rutgers method, but there are only two choices for this method, and they correspond to positive or negative. Compared to the theoretical values, data obtained by the colorimetric method ranged from 1.5 to 18.1% high, with a coefficient of variation of 4.4 to 13.4%. These variations were assumed satisfactory considering the levels at which phosphatase was tested.

Determination of Alkaline Phosphatase in Casein: Collaborative Study

1981 ◽  
Vol 64 (3) ◽  
pp. 623-627
Author(s):  
Gopala K Murthy ◽  
James T Peeler ◽  
◽  
E E Bone ◽  
B Dickerson ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Collaborative Study ◽  
Magnesium Acetate ◽  
Colorimetric Test

Abstract A collaborative study was made to determine alkaline phosphatase in casein samples by the rapid colorimetric test. Six to eight collaborators tested 10 unknown casein samples containing various amounts of residual phosphatase with and without the addition of magnesium acetate. Results indicated that magnesium acetate significantly increased phosphatase activity. The collaborators correctly analyzed 95% of the samples with the added magnesium acetate. The method has been adopted official first action.

Rapid Screening Method for Alkaline Phosphatase Activity in Cheese: Collaborative Study

1978 ◽  
Vol 61 (5) ◽  
pp. 1035-1037
Author(s):  
Dick H Kleyn
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Collaborative Study ◽  
Screening Method ◽  
Rapid Screening ◽  
Butanol Extract ◽  
Rapid Screening Method

Abstract The method developed for determining alkaline phosphatase activity in cheese, in which phenolphthalein monophosphate is used as the substrate, was collaboratively studied. A 7.5% butanol extract of cheese is reacted with phenolphthalein monophosphate; phenolphthalein is released and yields a red solution that is compared visually with a standard (s) prepared from the same extract. Seven collaborators analyzed 8 samples of cheese, in duplicate, by the screening method and Scharer I method. Of the 208 observations returned, only 4 were incorrect. The alkaline phosphatase method has been adopted as official first action.

LEUCOCYTE METABOLISM IN PREGNANCY

1960 ◽  
Vol XXXV (IV) ◽  
pp. 575-584 ◽  
Author(s):  
C. Borel ◽  
J. Frei ◽  
A. Vannotti
Keyword(s):  
Alkaline Phosphatase ◽  
Oxygen Consumption ◽  
Pregnant Women ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Lactate Production ◽  
Glucose Consumption ◽  
In Pregnancy

ABSTRACT Enzymatic studies, on leucocytes of pregnant women, show an increase of the alkaline phosphatase activity and a decrease of the glucose consumption and lactate production, as well as of proteolysis. The oxygen consumption, with succinate as substrate, does not vary.

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