Abstract: Aspects of the disclosure provide a method. The method includes forming a structure over a substrate, and forming a spacer layer on the structure, wherein the spacer layer has a recess. The method includes forming a mask layer over the spacer layer and in the recess, the mask layer including a first layer, a second layer and a third layer. The method includes patterning the third layer of the mask layer, and etching the first layer and the second layer of the mask layer to form an opening to expose the recess of the spacer layer, wherein the opening in the second layer has a first width; and. The method includes removing the second layer using a wet etchant, wherein the opening in the third layer has a second width, and the second with is greater than the first width.

Abstract: Disclosed is a method and a device for determining whether a sample contains ampicillin-resistant (AMP-R) non-typhoid Salmonella (NTS). The method comprises detecting, in the sample, the presence of a combination of certain genes or their gene products, wherein the presence of said combination indicates the sample contains AMP-R NTS.