Apparatus and associated methods relate to a device for performing single-cell native western blotting. In an illustrative example, the device, for example, includes a microfluidic flow chamber. The microfluidic flow chamber may, for example, include a chamber configured to receive a micropatterned gel array. The microfluidic flow chamber may, for example, include opposing electrodes located on opposing sides of the chamber configured for electrophoresis. The microfluidic flow chamber may, for example, include a flow-in-port configured to receive buffer fluid into the chamber. The microfluidic flow chamber may, for example, include a flow-out-port configured to receive buffer fluid out of the chamber. Associated methods include a method of performing single-cell native western blotting. The method includes providing a patterned polyacrylamide gel slide formed by casting a polyacrylamide gel layer between a surface-treated microscope slide and a photoresist-patterned silicon wafer.

Provided herein are methods, compositions, kits, and systems for detecting Epstein Barr virus infection (EBV) in gastric cancer (GC) patients. In particular, provided herein are methods, composition, kits, and systems for diagnosing and treating EBV-positive gastric cancer (EBV.sup.+ GC) in a biological sample of an individual based on the presence and level of antibodies against particular Epstein Barr virus proteins. EBV.sup.+ GC is a distinct subtype of gastric cancer and is associated with unique molecular profiles. Also provided herein are methods for providing more personalized therapy for each of these distinct cancer subtypes and methods for determining an Epstein Barr virus-positive gastric cancer antibody signature, and kits comprising components and protocols for performing the methods of this disclosure.