scholarly journals Comparative Analysis of the Standard Methods Methylene Blue Stain and Advantages of the Polychrome and Acid-and-Water-Free Stains in the Direct Microscopic Examination of Milk

1949 ◽  
Vol 39 (9) ◽  
pp. 1110-1119 ◽  
Author(s):  
Benjamin S. Levine ◽  
Luther A. Black
Keyword(s):  
Methylene Blue ◽  
Comparative Analysis ◽  
Microscopic Examination ◽  
Standard Methods ◽  
Direct Microscopic Examination ◽  
Blue Stain

A COMPARATIVE STUDY OF STAINS PROPOSED FOR THE DIRECT MICROSCOPIC EXAMINATION OF MILK

1951 ◽  
Vol 14 (2) ◽  
pp. 49-64 ◽  
Author(s):  
Joseph C. Olson ◽  
Luther A. Black
Keyword(s):  
Methylene Blue ◽  
Potassium Dichromate ◽  
Collaborative Study ◽  
Laboratory Procedure ◽  
Standard Methods ◽  
Weighted Averages ◽  
Counting Procedure ◽  
Direct Microscopic Examination ◽  
Blue Stain ◽  
Microscopic Counting

Five stains which have been proposed as substitutes for stains now specified in Standard Methods were compared by means of a collaborative study involving nine different laboratories. Stain I was the present Standard Methods alcohol-containing methylene blue stain; Stain II was a potassium - dichromate - sulfuric acid polychrome methylene blue stain; Stain III was an acid- and water-free methylene blue stain; Stain IV was a modification of Stain III containing hydrogen peroxide; Stain V was a methylene blue stain, the use of which was accompanied by a modification in fixation of the milk film; and Stain VI was a modified two color stain, details of which were not supplied. Examination of weighted averages of all samples from all laboratories showed that Stain III yielded the highest average count. Unfavorable comments pertaining to all stains except Stain III were received. Great variation in the results between laboratories was evident. One stain might show superior results in one laboratory and give inferior results in another laboratory. In general, Stain III showed the least variation in results among the collaborating laboratories, although it obtained the highest score in only one laboratory. The study pointed up the need for uniformity in laboratory procedure among different laboratories, particularly as regards the direct microscopic counting procedure.

A DIRECT MICROSCOPIC METHOD FOR DETECTING ANTIBIOTIC ACTIVITY IN MILK1

1960 ◽  
Vol 23 (4) ◽  
pp. 117-121 ◽  
Author(s):  
B. J. Liska
Keyword(s):  
Methylene Blue ◽  
Microscopic Examination ◽  
Test Procedure ◽  
Streptococcus Thermophilus ◽  
Antibiotic Activity ◽  
Microscopic Method ◽  
Permanent Record ◽  
Milk Samples ◽  
Blue Stain

A method for detecting antibiotic activity in milk using microscopic examination is presented. The Streptococcus thermophilus culture is exposed to the milk samples for 60–90 min. at 37°C. A methylene blue stain is prepared and examined for changes in morphology or reduction in clump count as compared to a control in antibiotic free milk. Abnormal enlargement or elongation of cells or a 50% reduction in clump count as compared to the control indicates antibiotic activity. Minimum concentrations of various antibiotics detected are: penicillin 0.015 units per ml; bacitracin 0.01 units per ml; terramycin 0.15 micrograms per ml; aureomycin 0.15 micrograms per ml and streptomycin 0.75 micrograms per ml. The test procedure is not affected by normal residues of sanitizers or bacteriophage. The stained milk films can be kept as a permanent record. Leucocycte counts can be made on the stained milk films during microscopic examination.

Designing Compressed Reinforcement Cross-Sections by Curvature and Nominal Stiffness Methods

2015 ◽  
Vol 797 ◽  
pp. 69-78
Author(s):  
Krzysztof Kamiński ◽  
Piotr Nowicki
Keyword(s):  
Reinforced Concrete ◽  
Comparative Analysis ◽  
Cross Sections ◽  
Concrete Columns ◽  
Computer Programs ◽  
Significant Issue ◽  
Reinforced Concrete Columns ◽  
Small Eccentricity ◽  
Standard Methods ◽  
Surface Reinforcement

The paper attempts to discuss the still significant issue of methods of design of the reinforced concrete columns according to PN-EN 1992-1-1:2008/A1:2015-03. Two algorithms of the dimensioning sections were developed according to two standard methods of dimensioning eccentrically compressed sections: the method of nominal stiffness (NS) and the method of nominal curvature (NC). Using both algorithms, computer programs in Excel were created. A comparative analysis of several examples of calculation were performed to compare the results of dimensioning of sections eccentrically compressed. The results obtained by the NC method give about 10% less surface reinforcement when loaded with big eccentricity and over 50% less when small eccentricity is applied.

A COMPARISON OF SIX METHODS OF PREPARING AND USING THE METHYLENE BLUE STAIN FOR BACTERIAL COUNTS BY THE DIRECT MICROSCOPIC METHOD*

1954 ◽  
Vol 17 (6) ◽  
pp. 179-184 ◽  
Author(s):  
Nathan Mantel ◽  
A. H. Robertson
Keyword(s):  
Methylene Blue ◽  
Federal State ◽  
Cooperative Study ◽  
Microscopic Method ◽  
Bacterial Counts ◽  
Blue Stain ◽  
Microscopic Count

A cooperative study, involving 12 federal, state, local, and private laboratories throughout the country, was conducted to evaluate six methods of preparing and using the methylene blue stain for the direct microscopic count of bacteria in milk. Three of the six methods were found superior, yielding significantly higher bacteria counts, at the same time providing greater ease in counting. These three methods are: Levine and Black's acid-and-water-free stain; North's aniline oil stain; and Anderson's polychrome stain.

Sign in / Sign up

Export Citation Format

Share Document