Provided herein are methods for processing and/or detecting a sample. A method can comprise providing a barrier between a first region and a second region, wherein the first region comprises the sample, wherein the barrier maintains the first region at a first atmosphere that is different than a second atmosphere of the second region, wherein a portion of the barrier comprises a fluid in coherent motion; and using a detector at least partially contained in the first region to detect one or more signals from the sample while the first region is maintained at the first atmosphere that is different than the second atmosphere of the second region. The portion of the barrier comprising fluid may have a pressure lower than the first atmosphere, the second atmosphere, or both.