The development of a hollow cap thermoplastic film for laser capture microdissection with a near field fiber tip

Our new constructed LCM system with a near field fiber probe heated the thermoplastic polymer film which placed above the tissue section by focusing laser beam (810 nm), and this method improved the resolution of the dissection capture. In this study, we designed a new cap with a hole, which made the fiber probe exert close melting, and the optimal conditions of making the thermoplastic film adhere on the cap were also studied. We used a copolymer with ethylene vinyl acetate (EVA) as the main material of the film and 0.001 M infrared naphthalocyanine dye dissolved in toluene were added and mixed for spin coating. The thermoplastic film was coated on a release agent sprayed substrate, and the new cap was placed on the substrate then put into the oven at 80°C for one hour. After cooling to the room temperature, we got the thermoplastic film on the cap, and we investigated the effect of different thickness of the thermoplastic film. By using the LCM system with near-field fiber probe, the melted spots have successfully formed on the films, and the results showed that the melted size is related to the thickness of the film. According to the results of this study, the fiber probe was workable on the hollow cap with thermoplastic film, and these provided the further development of the new LCM system in nano-captures.