Tandem microfluidic chip isolation of prostate and breast cancer cells from simulated liquid biopsies using CD71 as an affinity ligand

Simple Staining of Cells on a Chip

Simple staining of cells is a widely used method in basic medical diagnostics, education, and research laboratories. The stains are low-cost, but the extensive consumption results in excessive toxic waste generation. Thus, to decrease the amount of toxic waste resulting from the cell staining procedure is a need. In this study, we developed a magnetically driven and compartmentalized passive microfluidic chip to perform simple staining of human eukaryotic cells, K562 cells, and lymphocyte cells derived from patients. We demonstrated simple staining on cells with trypan blue, methylene blue, crystal violet, and safranin for high, medium, and low cell densities. The stained cells were imaged using a bright field optical microscope and a cell phone to count cells on the focal plane. The staining improved the color signal of the cell by 25-135-pixel intensity changes for the microscopic images. The validity of the protocol was determined using Jurkat and MDA-MB-231 cell lines as negative controls. In order to demonstrate the practicality of the system, lymphocyte cells derived from human blood samples were stained with trypan blue. The color intensity changes in the first and last compartments were analyzed to evaluate the performance of the chip. The developed method is ultra-low cost, significantly reduces the waste generated, and can be integrated with mobile imaging devices in terms of portability. By combining microfabrication technology with cell staining, this study reported a novel contribution to the field of microfluidic biosensors. In the future, we expect to demonstrate the detection of pathogens using this method.

High-recovery sorting of cancer cells from whole blood via periodic-focusing inertial microchip

Inertial microfluidic devices continue to show promise for label-free separation of cells from liquid biopsies and other biological samples.

A comparison of transferrin-receptor and epithelial cellular adhesion molecule targeting for microfluidic separation of cancer cells

Microfluidic, flow cytometry, and immunomagnetic methods for cancer cell isolation have heavily relied on the Epithelial Cellular Adhesion Molecule (EpCAM) for affinity separation. While EpCAM has been used extensively for circulating tumor cell isolation, it cannot be used to isolate non-epithelial cells. The human transferrin receptor (CD71) can also be used for cancer cell isolation and has the advantage that as an affinity target it can separate virtually any cancer cell type, regardless of disease origin. However, direct comparison of the capture ability of EpCAM and CD71 has not been reported previously. In this work, cell capture with both EpCAM and CD71 were studied using a novel higher-throughput herringbone cell separation microfluidic device. Five separation chip models were designed and the one with the highest capture efficiency (average 90 ± 10%) was chosen to compare antigen targets for cell capture. Multiple cancer cell lines including CCRF-CEM, PC-3 and MDA-MB-231 were tested for cell capture performance using both ligands (anti-CD71 and anti-EpCAM) in the optimized chip design. PC-3 and MDA-MB-231 cells were spiked into blood at concentrations ranging from 0.5%-10%. PC-3 cells were separated by anti-CD71 and anti-EpCAM with 32-37% and 31-50% capture purity respectively, while MDA-MB-231 were separated with 35-53% and 33-56% capture purity using anti-CD71 and anti-EpCAM for all concentrations. The enrichment factor for the lowest concentrations of cells in blood ranged from 66-74X. The resulting enrichment of cancer cells shows that anti-CD71 was found to be statistically similar to anti-EpCAM for epithelial cancer cells, while anti-CD71 can be further used for non-epithelial cells, where anti-EpCAM cannot be used.

Recent trends in sorbents for bioaffinity chromatography

Isolation or enrichment of biological molecules from complex biological samples is mostly a prerequisite in proteomics, genomics, and glycomics. Different techniques have been used to advance the efficiency of the purification of biological molecules. Bioaffinity chromatography is one of the most powerful technique that plays an important role in the isolation of target biological molecules by the specific interactions with ligands that are immobilized on different support materials. This review examines the recent developments in bioaffinity chromatography particularly over the past 5 years in the literature. Also properties of supports, immobilization techniques, types of binding agents, and methods used in bioaffinity chromatography applications are summarized.