Further Observations on the Microbiological Assay for Vitamin B12 Using Lactobacillus leichmannii.

1951 ◽  
Vol 76 (4) ◽  
pp. 806-810 ◽  
Author(s):  
H. P. Broquist ◽  
E. L. R. Stokstad ◽  
T. H. Jukes
Keyword(s):  
Vitamin B12 ◽  
Microbiological Assay ◽  
Lactobacillus Leichmannii

THE CONSTITUENTS OF COD LIVER WITH VITAMIN B12 ACTIVITY FOR LACTOBACILLUS LEICHMANNII

1956 ◽  
Vol 34 (2) ◽  
pp. 191-196
Author(s):  
Beryl Truscott ◽  
P. L. Hoogland
Keyword(s):  
Ion Exchange ◽  
Vitamin B12 ◽  
Microbiological Assay ◽  
Countercurrent Distribution ◽  
Vitamin B ◽  
Partition Chromatography ◽  
Total Vitamin ◽  
Beef Liver ◽  
Fractionation Procedure ◽  
Lactobacillus Leichmannii

The identity of the compounds that together form the total microbiological vitamin B12 activity of cod-liver residue was determined by a fractionation procedure involving ion exchange, countercurrent distribution, partition chromatography, and microbiological assay. The presence of cyanocobalamin, hydroxocobalamin, and the desoxyribosides of thymine, uracil, hypoxanthine, xanthine, and guanine was demonstrated. The total vitamin B12 activity, as determined by microbiological assay with Lactobacillus leichmannii, and its distribution in cod-liver residue, were very similar to those of beef liver. Cod-liver residues may be used to replace beef liver in vitamin B12 preparations.

Commercially-supplied binders for plasma cobalamin (vitamin B12), analysis--"purified" intrinsic factor, “cobinamide"-blocked R-protein binder, and non-purified intrinsic factor-R-protein binder--compared to microbiological assay.

1980 ◽  
Vol 26 (5) ◽  
pp. 598-600 ◽  
Author(s):  
N P Kubasik ◽  
M Ricotta ◽  
H E Sine
Keyword(s):  
Protein Binding ◽  
Vitamin B12 ◽  
Intrinsic Factor ◽  
Microbiological Assay ◽  
Binding Agents ◽  
Lactobacillus Leichmannii

Abstract Recent evidence (Kolhouse et al., N. Engl. J. Med. 299: 785–792, 1978) demonstrates that commercial cobalamin (Vitamin B12) radioassay kits contain nonspecific R-protein binding agents that can give falsely normal results in patients who are actually cobalamin deficient. We tested three kits: with “purified” intrinsic factor as the binder, with intrinsic factor and the nonspecific R-protein sites blocked with “cobinamide,” and non-purified intrinsic factor-R-protein binder. Results with use of the first two compared well with those by a microbiological assay (Lactobacillus leichmannii) and are in harmony with clinical impressions.

The Vitamin B12 Content of Certain Fishery Materials

1953 ◽  
Vol 10 (2) ◽  
pp. 64-68 ◽  
Author(s):  
B. A. Southcott ◽  
H. L. A. Tarr
Keyword(s):  
Vitamin B12 ◽  
Chromatographic Separation ◽  
Growth Response ◽  
Microbiological Assay ◽  
Vitamin B ◽  
Hexane Extraction ◽  
Clupea Pallasi ◽  
Assay Procedure ◽  
Lactobacillus Leichmannii

Irregularities occurring in the microbiological assay of herring (Clupea pallasi) materials for vitamin B12 (cobalamin) are described and the probable reasons for the differences discussed. With the employment of a Lactobacillus leichmannii assay procedure and conditions under which vitamin B12 (cyano-cobalamin) and vitamin B13a (hydroxo-cobalamin) caused identical growth response, it was found that normal commercial flame-dried herring meals had about the same total cobalamin content as specially prepared meals dried at 38° to 43.5 °C. Chromatographic separation, elution and assay of the cobalamins in herring-meal samples indicated that substantially all of the activity found by direct assays of the meals was due to the vitamin itself. Hexane extraction had little effect on the cobalamin content, but heating the meals reduced it.

THE CONSTITUENTS OF COD LIVER WITH VITAMIN B12 ACTIVITY FOR LACTOBACILLUS LEICHMANNII

1956 ◽  
Vol 34 (1) ◽  
pp. 191-196
Author(s):  
Beryl Truscott ◽  
P. L. Hoogland
Keyword(s):  
Ion Exchange ◽  
Vitamin B12 ◽  
Microbiological Assay ◽  
Countercurrent Distribution ◽  
Vitamin B ◽  
Partition Chromatography ◽  
Total Vitamin ◽  
Beef Liver ◽  
Fractionation Procedure ◽  
Lactobacillus Leichmannii

The identity of the compounds that together form the total microbiological vitamin B12 activity of cod-liver residue was determined by a fractionation procedure involving ion exchange, countercurrent distribution, partition chromatography, and microbiological assay. The presence of cyanocobalamin, hydroxocobalamin, and the desoxyribosides of thymine, uracil, hypoxanthine, xanthine, and guanine was demonstrated. The total vitamin B12 activity, as determined by microbiological assay with Lactobacillus leichmannii, and its distribution in cod-liver residue, were very similar to those of beef liver. Cod-liver residues may be used to replace beef liver in vitamin B12 preparations.

scholarly journals THE MICROBIOLOGICAL ASSAY OF VITAMIN B12 WITH LACTOBACILLUS LEICHMANNII

1949 ◽  
Vol 181 (2) ◽  
pp. 635-644
Author(s):  
C.E. Hoffmann ◽  
E.L.R. Stokstad ◽  
B.L. Hutchings ◽  
A.C. Dornbush ◽  
Thomas H. Jukes
Keyword(s):  
Vitamin B12 ◽  
Microbiological Assay ◽  
Lactobacillus Leichmannii

A Microbiological Assay for Vitamin B12 Using Lactobacillus leichmannii.

1949 ◽  
Vol 72 (2) ◽  
pp. 515-521 ◽  
Author(s):  
H. T. Peeler ◽  
H. Yacowitz ◽  
L. C. Norris
Keyword(s):  
Vitamin B12 ◽  
Microbiological Assay ◽  
Lactobacillus Leichmannii

scholarly journals Study on the microbiological assay for vitamin B12 of UHT cow's milk and infant formula using Lactobacillus leichmannii.

1989 ◽  
Vol 36 (5) ◽  
pp. 409-416 ◽  
Author(s):  
Toshiro KAMEI ◽  
Jun SATO ◽  
Yasuko SUGIMOTO ◽  
Naoko SUZUKI ◽  
Katsuhiko NODA
Keyword(s):  
Vitamin B12 ◽  
Infant Formula ◽  
Microbiological Assay ◽  
Cow’S Milk ◽  
Cow's Milk ◽  
Lactobacillus Leichmannii

scholarly journals OBSERVATIONS ON THE USE OF LACTOBACILLUS LEICHMANNII 4797 IN THE MICROBIOLOGICAL ASSAY OF VITAMIN B12

1950 ◽  
Vol 184 (1) ◽  
pp. 211-221
Author(s):  
Helen R. Skeggs ◽  
Helga M. Nepple ◽  
Katherine A. Valentik ◽  
Jesse W. Huff ◽  
Lemuel D. Wright
Keyword(s):  
Vitamin B12 ◽  
Microbiological Assay ◽  
Lactobacillus Leichmannii

Commercially-supplied binders for plasma cobalamin (vitamin B12), analysis--"purified" intrinsic factor, “cobinamide"-blocked R-protein binder, and non-purified intrinsic factor-R-protein binder--compared to microbiological assay.

1980 ◽  
Vol 26 (5) ◽  
pp. 598-600
Author(s):  
N P Kubasik ◽  
M Ricotta ◽  
H E Sine
Keyword(s):  
Protein Binding ◽  
Vitamin B12 ◽  
Intrinsic Factor ◽  
Microbiological Assay ◽  
Binding Agents ◽  
Lactobacillus Leichmannii

Abstract Recent evidence (Kolhouse et al., N. Engl. J. Med. 299: 785–792, 1978) demonstrates that commercial cobalamin (Vitamin B12) radioassay kits contain nonspecific R-protein binding agents that can give falsely normal results in patients who are actually cobalamin deficient. We tested three kits: with “purified” intrinsic factor as the binder, with intrinsic factor and the nonspecific R-protein sites blocked with “cobinamide,” and non-purified intrinsic factor-R-protein binder. Results with use of the first two compared well with those by a microbiological assay (Lactobacillus leichmannii) and are in harmony with clinical impressions.

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