Extraction of serum vitamin B12 for radio-isotopic and Lactobacillus leichmannii assay.

Abstract

RADIO-ISOTOPIC STUDIESThe radio-isotopic assay was that of Lau et al (1965) modified by Raven et al (1969). Individual backgrounds were used for each serum sample, and the normal range for this method is 200-1000 pg/ml. In this method, serum vitamin B12 is extracted from its binding proteins by the heating of serum in the presence of cyanide and N/4 HCI. A turbid solution is obtained and no precipitation of protein occurs (fig 1). L. leichmannii Serum ExtractsInto a 20 ml screw-capped glass universal container are placed 1 ml serum, 8 ml water, 0-5 ml 01 % NaCN solution, and 0-25 ml 0-4M acetate buffer (pH 4 5). With the screw cap in place, the container is heated at 11 5°C for 10 minutes and, after cooling, 0-25 ml phosphate buffer (M/5 K2HPO4) is added.The container is then centrifuged and 8 ml of the clear supernatant (equivalent to 0-8 ml serum) is transferred to another universal container together with 2 ml N/4 HCI. This acid-serum extract mixture is then treated as in the radio-isotopic assay above. 531 on 10 May 2018 by guest. Protected by copyright.

Prevalence of Ferritin, Folate and Vitamin B12 Deficiencies Amongst Children in 5–18 years of Age in Delhi

“…Serum B12 was estimated utilizing the radio isotopic. The levels less than 200 pg/mL were considered as indicative of cobalamin deficiency [3].Prevalence of ferritin, folate and B12 deficiencies were observed to be 54.5 %, 42.0 % and 67.2 % for children in the age group of 5-11 y, and 55.0 %, 30.7 % and 68.3 % for children in the age group of 12-18 y, respectively.An earlier community based study documented that 88 % of the children below 6 y had low serum ferritin levels [4]. Similarly, the prevalence of folate deficiency as 50 % and cobalamin deficiency as 62 % has been reported earlier [5].…”

“…Serum B12 was estimated utilizing the radio isotopic. The levels less than 200 pg/mL were considered as indicative of cobalamin deficiency [3].…”