Glass Chemistry to Analyze Human Cells under Adverse Conditions

Abstract

Emerging point-of-care diagnostic tests capable of analyzing whole mammalian cells often rely on the attachment of harvested cells to glass surfaces for subsequent molecular characterization. We set out to develop and optimize a kit for the diagnosis of lymphoma in low- and middle-income countries where access to advanced healthcare testing is often absent or prone to error. Here, we optimized a process for the lyophilization of neutravidin-coated glass and cocktails of antibodies relevant to lymphoma diagnosis to establish long-term stability of reagents required for point-of-care cell capture technology. Lyophilized glass slides showed no decline in their performance compared to freshly prepared neutravidin glass and preserved capture efficiency for 5 weeks under easily attainable storage conditions. We demonstrate the successful performance of the low-cost, lyophilized kit in a cell capture assay to enable true point-of-care analyses under adverse conditions. We anticipate that the strategy can be expanded to other cancer cell types or cell-derived vesicle analysis.

CytoPAN—Portable cellular analyses for rapid point-of-care cancer diagnosis

“…One of the key design elements in the current system is lyophilized kits containing all necessary antibodies, buffers, and other reactants. A similar approach had previously been realized for lymphoma (44) but nevertheless required re-analysis for breast cancer because it required us to target different markers. Major advantages of these freeze-dried kits include: i) expanding the shelf-life of kits from hours to weeks or months, a critical factor for field testing; ii) enabling storage in regular refrigerators rather than specialty freezers commonly unavailable in LMICs;…”