Contents lists available at ScienceDirect Journal of Neuroscience Methods journal homepage: www.elsevier.com/locate/jneumeth A mechanized device for mounting histological tissue sections Osama Habbal a , Ahmad Farhat b , Reem Khalil c, ⁎ a American University of Sharjah, Department of Mechanical Engineering, Sharjah, UAE b American University of Sharjah, Sharjah, UAE c American University of Sharjah, Department of Biology, Chemistry, and Environmental Sciences, Sharjah, UAE ARTICLE INFO Keywords: Histology Tissue sections Mounting method Ferret brain Additive manufacturing 3d printing ABSTRACT Background: Traditional methods for mounting tissue sections onto slides are suboptimal as the amount of labor required quickly multiplies with increasing number of samples. Methods to accelerate the tissue mounting process while reducing the associated risk of tissue damage are needed. New Method: We designed and 3D printed a mechanized device with an inclined platform used to mount tissue sections onto slides in buffer solution. The main advantage of this design is to reduce the time required for mounting sections as well as minimize the possibility of damaging delicate or thin tissue sections. Results: Using our device, we illustrate and describe in detail the steps required to mount smaller coronally cut mouse brain sections, as well as bigger tangentially cut ferret brain sections. This method's efficiency was as- sessed by comparing the time required to mount an entire slide of ferret brain sections using our method and the conventional method. Using our device reduced the tissue mounting time by 60%. Comparison with Existing Method(s): Compared to existing conventional tissue mounting methods, our device is a simple and user friendly alternative that substantially reduces the time required to mount tissue sections while preserving tissue section quality. Conclusions: Using our device can streamline histological processing and prove to be especially useful for a variety of tissue types as the platform was designed to accommodate different size microscope slides, and thus use for varying tissue section sizes. 1. Introduction Neuroanatomy research has traditionally been rooted in the use of histology which has resulted in a wealth of structural data. Although new techniques have been developed to study the anatomy of the brain such as structural Magnetic Resonance Imaging (MRI) and Diffusion Tensor Imaging (DTI), histological analysis remains the gold standard used in anatomical studies. However, histological processing of brain tissue is a labor intensive, multi-step process comprising tissue sec- tioning, staining, and mounting of sections onto microscope slides. An especially critical step that requires meticulous care and patience is tissue mounting, which involves transferring cut tissue sections onto a slide. There is always some risk of damaged sections, even for expert users. Few attempts have been made to develop a process or create a de- vice for facilitating the mounting of such sections (Xiao and Levitt, 2005). Often the process of mounting tissue sections takes place over multiple attempts, which can often result in damaged sections and loss of time. One method commonly used to mount tissue sections is based on the general principle of attaching a substrate to the surface of the frozen tissue block and simultaneously cutting the tissue together with the supporting substrate (Bush, 1952; Collewijn and Noorduin, 1969). To place the tissue on a glass slide, the substrate containing the cut section is pushed against the glass slide and thawed by applying pres- sure with the finger. The advantage of using this approach is the direct mounting of sections from the microtome blade onto slides while minimizing tissue distortions. However, this method is incompatible with histological protocols that require staining of free-floating tissue sections. Additionally, the user cannot transfer the tissue sections into cryoprotectant solution to store for later processing. Alternatively, tissue sections may be mounted onto glass slides from buffer solution in a petri dish. This works by submerging a glass slide at an angle into a petri dish containing a buffer solution, and carefully drawing a suspended tissue section from solution onto the slide using a fine tip brush (Kapelsohn, 2015). This method poses several challenges. Delicate tissue sections are often prone to folding and tearing as the user reorients and moves the section onto the slide. Furthermore, this process becomes particularly difficult to complete as the user https://doi.org/10.1016/j.jneumeth.2019.03.012 Received 26 December 2018; Received in revised form 16 March 2019; Accepted 19 March 2019 ⁎ Corresponding author. E-mail address: rkhalil@aus.edu (R. Khalil). Journal of Neuroscience Methods 320 (2019) 72–78 Available online 25 March 2019 0165-0270/ © 2019 Elsevier B.V. All rights reserved. T