PT - JOURNAL ARTICLE AU - Boczarow, Borys TI - The influence of penicillin on <em>Lactobacillus leichmannii</em> serum B<sub>12</sub> assay AID - 10.1136/jcp.14.2.189 DP - 1961 Mar 01 TA - Journal of Clinical Pathology PG - 189--192 VI - 14 IP - 2 4099 - http://jcp.bmj.com/content/14/2/189.short 4100 - http://jcp.bmj.com/content/14/2/189.full SO - J Clin Pathol1961 Mar 01; 14 AB - The influence of penicillin on vitamin B12 assay using L. leichmannii as the test organism was investigated, and it was found that penicillin even in a low serum concentration invalidated the test.