Assay chip Fluidic 638 e.g. for cell-based assays that can be operated using hydrostatic pressure generated by attached liquid filled tanks. The chip features Luer interfaces with piercing structures which can only be used with male Luer tanks. The interfaces are not compatible with male Luer connectors. The chip features liquid-tight venting membranes at the end of the waste channel to allow air-release but prevent liquid spillage.