Broad Bands Observed in Serum Electrophoresis Should Not Be Taken Lightly

[...]the y-HC typically presents as a broad band, which could be suggestive of the presence of polyclonal protein (1, 8). [...]the y-HC often migrates as a low-concentration M protein in the ß, and even a2, region, where it could be partly masked by other serum proteins within the a2/ß region (2, 8). [...]IFE provides only indirect evidence in which the absence of light chains is indicative of free heavy chain. [...]this requires that alternative explanations for the missing light chains be excluded because poor reactivity of reagents with light chains or the antigen-excess phenomenon may all lead to failure to detect light chains (8, 9). Because ofthese analytical challenges, we advise confirming each heavy chain with at least 1 alternative analytical method to IFE that, if needed, is outsourced to a specialized laboratory.