Different patterns of centrin staining. The isotypic PCs were identified by cytoplasmic κ or λ light-chain antibody conjugated with AMCA (cIg, blue), and centrin was stained with anticentrin2 conjugated with Alexa 488 (arrow; green). (A) Most PCs from healthy donors had no signals. (B-C) Cells with 1 to 4 signals were considered to have normal centrosome. (D-E) Centrosome amplification was seen in typical clonal PCs as well as the rare multinucleated PCs in patients. Various centrosome abnormalities were seen as follows: (D-E) increased number of signals in a cluster, (F) increased signals that were scattered, (G) coalescence of centrins into string-like structures, and (H) centrins staining up as ring-like structure. Abnormal centrosome structure as seen in panels F to H were predominantly seen in MM. The cells were visualized with a Leitz Epifluorescence microscope using a 100 ×/1.4 NA oil objective lens (Leitz, Wetzlar, Germany). The images were captured with the CoolSNAP ES CCD camera (Photometrics, Tucson, AZ) and acquired using either the Vysis smart capture software (Vysis, Downer's Grove, IL) or Oncor imaging system software (Oncor, Gaithersburg, MD). The acquired images were subsequently processed with Adobe Photoshop 7.0 (Adobe Systmes, San Jose, CA).