Detection of circulating melanoma cells by immunomagnetic cell sorting

Abstract

We developed a cellular approach to the identification of circulating melanoma cells in peripheral blood using immunomagnetic cell sorting. One hundred seventy-eight blood samples from 129 melanoma patients and 30 samples from healthy persons and nonmelanoma patients were examined. After density gradient centrifugation the interphase was incubated with the mAb 9.2.27. Positive cells were labeled with magnetic microbeads and enriched by immunomagnetic cell sorting. Cells were stained using an alkaline phosphatase-antialkaline phosphatase assay and examined by light microscopy. In spiking experiments, melanoma cells seeded at a concentration of one melanoma cell per ml whole blood could be detected reliably with the assay. Circulating melanoma cells were not found in 30 controls examined, nor were 9.2.27-positive cells found in 41 patients with primary malignant melanoma. In patients with regional lymph node metastases and in patients with disseminated disease, circulating 9.2.27-positive cells could be detected in 3 out of 22 patients (13.6%) and 10 out of 66 patients (15.2%) examined. We present a sensitive and specific immunocytological approach to detect circulating melanoma cells in peripheral blood. The method is not suitable for early detection of metastases but is a valuable tool for further investigating biological characteristics of circulating melanoma cells.

Aptamers from Cell-Based Selection for Bioanalytical Applications

“…This is consistent with current extraction efficiency values reported by immunomagnetic separation. 68,69 …”

Rapid and highly sensitive electrochemical determination of alkaline phosphatase using a composite tyrosinase biosensor

“…Moreover, its use as a tracer in immunoassays and molecular biology has become popular [5][6][7][8][9][10][11][12][13][14]. In general, enzyme immunoassays combine the speciWcity of the antigen-antibody reaction with the sensitivity and signal ampliWcation of enzyme-catalyzed reaction.…”

Aptamer Selection, Phage Display, and Sensor Development

“…The sensors that result are based on different materials, such as organic chemicals [78][79][80], organic polymers [81], proteins [82][83][84][85], or cells [86]. Remarkable progress has been made in developing fluorosensors for metal ions such as Ca 2+ , Zn 2+ , and Pb 2+ .…”

“…For instance, magnetic activated cell sorting (MACS) has been used extensively for extraction and enrichment of epithelial cells [81], endothelial cells [82], bacteria [83], and circulating tumor cells [84]. However, these methods, which utilize 65-nm silica-coated MNPs, typically use micrometer-sized magnetic polymer beads.…”