A schematic of the sampling setup for in situ imaging of the interaction of ASD with buffer is shown in Figure . The samples for SRS imaging were covered with a small, separately cut piece of cover glass (No. 1.5, EUKITT®, ORSAtec). The samples were then briefly heated from above using a hot air gun (Hot Air Rework Station CIF 852-A++, Farnell), allowing the top of the film to soften while gently pressing the cover glass down to adhere it to the film. This preparation method allowed the subsequently added buffer to penetrate only from the side of the film and not the top or bottom, such that the interaction of the ASD components perpendicular to the initial ASD-buffer interface could be imaged in situ.