Serum protein electrophoretic analysis and phage immunoblot, patients 12 and 20. The paraproteins are evident on serum protein electrophoresis (SPEP) pattern (lane 1). The anode (positive pole) is toward the top, with albumin (ALB) being the most anodal serum protein visible in the gel. The serum paraprotein is denoted with →. For patient 12 (lefthand gel), lane 2 is probed with phage clone 20-41, which expresses a peptide associated with the AD-2S1 epitope of HCMV glycoprotein B. Lane 3 is an irrelevant phage clone. For patient 20, lanes 2 to 4 are replicates of lane 1, blotted onto a nitrocellulose membrane, and immunostained with various probes. Lane 2 was immunostained with a human IgG-specific antibody conjugate. Lanes 3 and 4 were immunostained with the indicated phage clones, which are also listed in Figure 2. Clone 20-61 is derived from motif 1, containing the UL-48 gene product paraprotein epitope. Sera are undiluted in lane 1, and diluted 1:100 for lanes 2 to 4. Appl pt denotes the gel application point, which sometimes yields a faint artifactual band.