Continuous-flow automation of the Lactobacillus casei serum folate assay.
نویسنده
چکیده
A method is described for the continuous-flow automation of the serum folate assay using Lactobacillus casei. The total incubation period is approximately four hours. The growth response of the organism to folate is estimated by measuring the rate of reduction of 2,3,5-triphenyl tetrazolium chloride (TTC). A simple continuous culture apparatus is used to grow the inoculum. Supplementation of the assay medium is necessary to obtain parallel results. A statistical assessment shows a favourable comparison with the whole-serum tube assay using a chloramphenicol resistant strain of L. casei. The method is less sensitive to inhibitory substances than the tube assay.
منابع مشابه
Cryoprotected Lactobacillus casei: an approach to standardization of microbiological assay of folic acid in serum.
Folate-depleted, cryoprotected preparations of Lactobacillus casei are stable for at least eight months at -18 degrees C, capable of reproducible growth and suitable as a ready source of inoculum for measurement of folates in physiological fluids. Cryoprotected microorganisms can be a commercially available laboratory reagent, thus simplifying and further standardizing the microbiological assay...
متن کاملSuperiority of simplified assay for folate with Lactobacillus casei ATCC 7469 over assay with chloramphenicol-adapted strain.
Direct assay of serum folate by mixing serum with a mixture of L. casei and medium without autoclaving was found to provide serum folate results similar to those by extraction of serum with heat. This procedure was found more reliable than that using the same technique with chloramphenicol and a strain of L. casei adapted to grow in this material. A portion of apparent folate activity assayed i...
متن کاملEffect of Tween 80 on incubation period of Lactobacillus casei assay of serum folate.
Contamination of folic acid assay medium with oleate led to a lag phase when Lactobacillus casei cultures were grown on folic acid but not when whole serum provided the folate source. This led to high assay values when using 20-hour incubation periods but satisfactory results were obtained after 48 hours' incubation. The addition of Tween 80 to the medium eliminated the lag phase and the assay ...
متن کاملRelative Folate Deficiency of Erythrocytes in Pernicious Anemia and Its Correction with Cyanocobalamin.
By Biuu’ ui n A. COOPER AND Louis LOWENSTEIN T HE DETERMINATION of folate activity in serum with Lactobacillus casei allows recognition of patients with folate deficien y.13 It has been observed that much of the L. casei-active folate in human serum consists of N5-methyl tetrahydropteroyl monoglutamate,4 and that the concentration of folate activity in serum is increased in some patients with p...
متن کاملEffect of light on the Lactobacillus casei icrobiological assay.
Because of the considerable differences in the reported values for serum folate in normal subjects using Lactobacillus casei as assay organism the effect of daylight when preparing media for this assay was studied. It was found that the growth properties of the medium were destroyed by direct sunlight and impaired by bright reflected sunlight, therefore reducing the sensitivity of the assay. Ad...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Journal of clinical pathology
دوره 30 12 شماره
صفحات -
تاریخ انتشار 1977