A comparison of seven strains of Lactobacillus casei var. rhamnosus in relation to their use in the microbiological assay of serum folate.

Summary. A comparison was made of 7 strains of Lactobacillus casei var. rhamnosus in relation to their use in the microbiological assay of serum folate. The problem of clumping by some strains could be overcome by the addition of extra salt, or chloramphenicol, to the medium. The strains showed differences in their tolerance to added salts which was measured as the Mean Inhibitory Salt Concentration. The highest salt concentration which could be used in the assay medium without affecting the serum folate results was about one-third of the Mean Inhibitory Salt Concentration and this could be less than the optimum concentration for growth. These differences in salt tolerance may provide a partial explanation of the variety of normal values reported from different laboratories.

[1]  I. Temperley,et al.  A comparison of serum folate estimations using two different methods. , 1973, Journal of clinical pathology.

[2]  Lee Rj,et al.  An automated method for microbiological assays. , 1973 .

[3]  I. Chanarin,et al.  Experience with microbiological assay for folate using a chloramphenicol-resistant L. casei strain , 1972, Journal of clinical pathology.

[4]  Withey Jl,et al.  An assessment of work simplified procedures for the microbiological assay of serum vitamin B12 and serum folate. , 1972 .

[5]  D. W. Neill,et al.  Use of the `Analmatic clinical system' in the microbiological assay of vitamin B12 and folic acid in serum , 1971, Journal of clinical pathology.

[6]  G B Tennant,et al.  A simple high-speed recording colorimeter system. , 1970, Journal of clinical pathology.

[7]  R. Davis,et al.  Automation of the assay of folate in serum and whole blood , 1970, Journal of clinical pathology.

[8]  R. Davis,et al.  An automated method for the measurement of folate activity , 1970, Journal of clinical pathology.

[9]  B. O'neill,et al.  Effect of incubation time on the L. casei bioassay of folic acid in serum. , 1969, Blood.

[10]  B. Anderson,et al.  Effect of light on the Lactobacillus casei microbiological assay , 1968, Journal of clinical pathology.

[11]  I. Temperley,et al.  Effect of ascorbic acid on the serum folic acid estimation , 1966, Journal of clinical pathology.

[12]  V. Herbert.  Aseptic addition method for Lactobacillus casei assay of folate activity in human serum , 1966, Journal of clinical pathology.

[13]  P. Reizenstein.  Errors and artefacts in serum folic-acid assays. Effects of age, food, drugs and radiation. , 2009, Acta medica Scandinavica.

[14]  T. A. Harper.  A Modified ‘Aseptic Addition’ Assay Procedure for the Measurement of serum ‘Folic-Acid’ Activity , 1965, Nature.

[15]  G. Spray.  Microbiological assay of folic acid activity in human serum , 1964, Journal of clinical pathology.

[16]  Kershaw Pw,et al.  SOME INVESTIGATIONS OF FOLIC-ACID DEFICIENCY. , 1964 .

[17]  W. Sims.  A PATHOGENIC LACTOBACILLUS. , 1964, The Journal of pathology and bacteriology.

[18]  D. Mollin,et al.  Studies on the folic acid activity of human serum , 1961, Journal of clinical pathology.