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Description
Life Sciences, 51(13), 1049-1056.

Laboratory interference: Persistent unexplained elevation may reflect macro-B12 (immunoglobulin-bound B12) or other assay interferences

Side-by-side comparisons over several months reveal changes that day-to-day observation misses
Sterilize the Stoppers: Vigorously wipe the top of each rubber stopper with a fresh alcohol pad