Novel PE and APC tandems: Additional near-infrared fluorochromes for use in spectral flow cytometry.

Recent advances in flow cytometry instrumentation and fluorochrome chemistries have greatly increased fluorescent conjugated antibody combinations that can be used reliably and easily in routine experiments. The Cytek Aurora flow cytometer was first released with three excitation lasers (405, 488, and 640 nm) and incorporated the latest Avalanche Photodiode (APD) technology, demonstrating significant improvement in sensitivity for fluorescent emission signals longer than 800 nm. However, there are limited commercially available fluorochromes capable of excitation with peak emission signals beyond 800 nm. To address this gap, we engineered six new fluorochromes: PE-750, PE-800, PE-830 for the 488 nm laser and APC-750, APC-800, APC-830 for the 640 nm laser. Utilizing the principal of fluorescence resonance energy transfer (FRET), these novel structures were created by covalently linking a protein donor dye with an organic small molecule acceptor dye. Additionally, each of these fluorochrome conjugates were shown to be compatible with fixation/permeabilization buffer reagents, and demonstrated acceptable brightness and stability when conjugated to antigen-specific monoclonal antibodies. These six novel fluorochrome reagents can increase the numbers of fluorochromes that can be used on a spectral flow cytometer.

Prognostic value of EpCAM/MUC1 mRNA-positive cells in non-small cell lung cancer patients.

The aim of this study was to assess the prognostic value of EpCAM/MUC1 mRNA-positive circulating tumor cells (CTCs) in patients with non-small cell lung cancer (NSCLC). The presence of EpCAM/MUC1 mRNA-positive CTCs was evaluated in 74 NSCLC patients before the initiation of any therapy, from which 61 patients with surgical resection of tumor were also evaluable for EpCAM/MUC1 mRNA-positive CTC analysis after surgery, by quantitative real-time PCR assay. Sixty patients with benign lung disease (BLD) entered this study as controls. The results showed that blood levels of EpCAM and MUC1 mRNA in NSCLC patients before and after surgery were significantly higher than those in BLD patients (P = 0.001 and P = 0.015, respectively, for EpCAM; P = 0.003 and P = 0.026, respectively, for MUC1), and the levels of the two gene mRNA in NSCLC patients significantly decreased after surgery (P = 0.025 and P = 0.033, respectively). Disease recurrence significantly increased in NSCLC patients with EpCAM/MUC1 mRNA-positive CTC preoperation and postoperation (P = 0.004 and P = 0.001, respectively). Disease-free survival and overall survival significantly reduced in patients with EpCAM/MUC1 mRNA-positive CTC preoperation and postoperation (P = 0.012 and P = 0.002, respectively, for preoperation; both P < 0.001 for postoperation). Multivariate analysis demonstrated that the presence of EpCAM/MUC1 mRNA-positive CTCs before and after surgery was an independent factor associated with disease recurrence. In conclusion, the detection of EpCAM/MUC1 mRNA-positive CTCs in the blood before and after surgery is useful for predicting a poor prognosis in NSCLC patients who undergo curative surgery.