{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,9,26]],"date-time":"2025-09-26T00:18:13Z","timestamp":1758845893402,"version":"3.44.0"},"reference-count":12,"publisher":"BMJ","issue":"4","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J Clin Pathol"],"published-print":{"date-parts":[[1981,4]]},"abstract":"<jats:p>It has been reported that serum vitamin B12 levels assayed by saturation analysis methods may give misleadingly high results, so much so that the diagnosis of vitamin B12 deficiency may be obscured. This defect was ascribed largely to assays using a vitamin B12 binder other than pure intrinsic factor. To test out this hypothesis two assays were set up, one using saliva (non-intrinsic factor R-binder) and the other using human gastric (intrinsic factor) as B12-binding agents. Both assays were able to differentiate sera from patients with pernicious anaemia from those from control subjects. Published results accumulated over the past 10 years indicate that properly designed and performed saturation analysis vitamin B12 assays are as reliable as microbiological assay methods for detecting low serum B12 levels. The failure of some methods to do does not appear to be due to the nature of the B12-binding agent.<\/jats:p>","DOI":"10.1136\/jcp.34.4.357","type":"journal-article","created":{"date-parts":[[2007,6,9]],"date-time":"2007-06-09T00:50:46Z","timestamp":1181350246000},"page":"357-360","source":"Crossref","is-referenced-by-count":8,"title":["Comparison of serum vitamin B12 estimation by saturation analysis with intrinsic factor and with R-protein as binding agents."],"prefix":"10.1136","volume":"34","author":[{"given":"R","family":"Zacharakis","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M","family":"Muir","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"I","family":"Chanarin","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[1981,4,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"816","DOI":"10.1056\/NEJM197810122991506","article-title":"Evidence that some patients with pernicious anaemia are not recognized by radiodilution assay for cobalamin in serum","volume":"299","author":"Cooper, B.A.; Whitehead, V.M.","year":"1978","unstructured":"Cooper BA, Whitehead VM. Evidence that some patients with pernicious anaemia are not recognized by radiodilution assay for cobalamin in serum. N Engl J Med 1978;299:816-8.","journal-title":"N Engl J Med"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"785","DOI":"10.1056\/NEJM197810122991501","article-title":"Cobalamin analogues are present in humanplasma and can mask cobalamin deficiency because current radioisotope dilution assays arenot specific for true cobalamin","volume":"299","author":"Kolhouse, J.F.; Kondo, H.; Allen, N.C.; Podell, E.; Allen, R.H.","year":"1978","unstructured":"Kolhouse JF, Kondo H, Allen NC, Podell E, Allen RH. Cobalamin analogues are present in humanplasma and can mask cobalamin deficiency because current radioisotope dilution assays arenot specific for true cobalamin. N EnglJ Med 1978;299:785-92.","journal-title":"N EnglJ Med"},{"issue":"74","key":"ref_3","first-page":"967","article-title":"with the use of saliva as the vitamin B12 binder","volume":"1969","author":"B.","unstructured":"B,, with the use of saliva as the vitamin B12 binder. J Lab Clin Med 1969;74:967-75.","journal-title":"J Lab Clin Med"},{"key":"ref_4","first-page":"453","article-title":"The carriers of native vitamin B12 in normal human serum","volume":"53","author":"Hall, C.A.","year":"1977","unstructured":"Hall CA. The carriers of native vitamin B12 in normal human serum. Clin Sci Mol Med 1977;53:453-7.","journal-title":"Clin Sci Mol Med"},{"key":"ref_5","first-page":"\"875","article-title":"Method for assay of human gastric intrinsic factor and for detection and titration of antibodies against intrinsic factor. Lancet 1963; ii: 1350-4. ' Gottlieb","volume":"25","author":"Ardeman, S.; Chanarin, I.","year":"1965","unstructured":"Ardeman S, Chanarin I. Method for assay of human gastric intrinsic factor and for detection and titration of antibodies against intrinsic factor. Lancet 1963;ii:1350-4. ' Gottlieb C, Lau K-S, Wasserman LR, Herbert V. Rapid charcoal assay for intrinsic factor (IF), gastric juice unsaturated B12 binding capacity, antibody to IF, and serum unsaturated B12 binding capacity. Blood 1965;25: 875-85. 7Donaldson RM Jr, Katz JH. Exchange between free and gastric juice-bound cyanocobalamin. J Clin Invest 1963; 42:534-45.","journal-title":"Blood; Rapid charcoal assay for intrinsic factor (IF), gastric juice unsaturated B12 binding capacity, antibody to IF, and serum unsaturated B12 binding capacity"},{"key":"ref_6","first-page":"\"*\" # \"457","article-title":"The megaloblastic anaemias","volume":"16","author":"Chanarin, I.","year":"1979","unstructured":"Chanarin I. The megaloblastic anaemias. 2nd edn. Oxford: Blackwell, 1979. * Britt RP, Bolton FG, Cull AC, Spray GH. Experience with a simplified method of radio-isotopic assay of serum vitamin B12. Br J Haematol 1969;16:457-64. '\u00b0 Frenkel EP, Keller S, McCall MS. Radioisotopic assay of serum vitamin B12 with the use of the DEAE cellulose. JLab Clin Med 1966;68:510-22.","edition":"2nd edn","journal-title":"Br J Haematol; Experience with a simplified method of radio-isotopic assay of serum vitamin B12"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"507","DOI":"10.1111\/j.1365-2141.1974.tb06816.x","article-title":"The use of chicken serum for measurement of serum vitamin B12 concentration by radioisotopic dilution: description of method and comparison with microbiological assay results","volume":"27","author":"Green, R.; Newmark, P.A.; Musso, A.M.; Mollin, D.L.","year":"1974","unstructured":"Green R, Newmark PA, Musso AM, Mollin DL. The use of chicken serum for measurement of serum vitamin B12 concentration by radioisotopic dilution: description of method and comparison with microbiological assay results. Br J Haematol 1974;27:507-26.","journal-title":"Br J Haematol"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"683","DOI":"10.1136\/jcp.20.5.683","article-title":"Results with radioisotopic assay of serum B12 using serum binding agent","volume":"20","author":"Matthews, D.M.; Gunasegaram, R.; Linnell, J.C.","year":"1967","unstructured":"Matthews DM, Gunasegaram R, Linnell JC. Results with radioisotopic assay of serum B12 using serum binding agent. J Clin Pathol 1967;20:683-6.","journal-title":"J Clin Pathol"},{"issue":"581-93","key":"ref_9","first-page":"14","article-title":"A simple routine radioisotopic method for the estimation of serum vitamin B12 using DEAE cellulose and human serum binding agent","volume":"21","author":"Wagstaff, M.; Broughton, A.","year":"1971","unstructured":"Wagstaff M, Broughton A. A simple routine radioisotopic method for the estimation of serum vitamin B12 using DEAE cellulose and human serum binding agent. Br J Haematol 1971;21:581-93, 14","journal-title":"Br J Haematol"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1136\/jcp.27.1.59","article-title":"Experience with a commercial kit for the radioisotopic assay of vitamin B12 in serum: the Phadebas B12 test","volume":"27","author":"Raven, J.L.; Robson, M.B.","year":"1974","unstructured":"Raven JL, Robson MB. Experience with a commercial kit for the radioisotopic assay of vitamin B12 in serum: the Phadebas B12 test. J Clin Pathol 1974;27:59-65.","journal-title":"J Clin Pathol"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1111\/j.1365-2141.1972.tb08783.x","article-title":"Comparison of three methods for measuring vitamin B12 in serum: Radioisotopic, Euglena gracilis and Lactobacillus leichmannii","volume":"22","year":"1972","unstructured":"Comparison of three methods for measuring vitamin B12 in serum: Radioisotopic, Euglena gracilis and Lactobacillus leichmannii. Br J Haematol 1972;22:21-31.","journal-title":"Br J Haematol"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1144","DOI":"10.5694\/j.1326-5377.1970.tb84480.x","article-title":"A modified isotopic dilution method for measuring the serum vitamin B12 level","volume":"1","author":"Shum, H.-Y.; Streeter, A.M.; O'Neill, B.J.","year":"1970","unstructured":"Shum H-Y, Streeter AM, O'Neill BJ. A modified isotopic dilution method for measuring the serum vitamin B12 level. 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J Aust"}],"container-title":["Journal of Clinical Pathology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/jcp.34.4.357","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,9,25]],"date-time":"2025-09-25T13:18:20Z","timestamp":1758806300000},"score":1,"resource":{"primary":{"URL":"https:\/\/jcp.bmj.com\/lookup\/doi\/10.1136\/jcp.34.4.357"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1981,4]]},"references-count":12,"journal-issue":{"issue":"4","published-online":{"date-parts":[[1981,4,1]]},"published-print":{"date-parts":[[1981,4]]}},"alternative-id":["10.1136\/jcp.34.4.357"],"URL":"https:\/\/doi.org\/10.1136\/jcp.34.4.357","relation":{},"ISSN":["0021-9746","1472-4146"],"issn-type":[{"type":"print","value":"0021-9746"},{"type":"electronic","value":"1472-4146"}],"subject":[],"published":{"date-parts":[[1981,4]]}}}