Single chain variable domain (Fv) fragments (scFv) are powerful tools in research and clinical settings, owing to better pharmacokinetic properties compared to the parent monoclonal antibodies and the relative ease of producing them in large quantities, at low cost. Though they offer several advantages, they suffer from lower binding affinity and rapid clearance from circulation, which limits their therapeutic potential. However, these fragments can be genetically modified to enhance desirable properties, such as multivalency, high target retention and slower blood clearance, and as such, a variety of scFv formats have been generated. ScFvs can be administered by systemic injection for diagnostic and therapeutic purposes. They can be expressed in vivo through viral vectors in instances where large infection rates and sustenance of high levels of the antibody is required. ScFvs have found applications as tools for in vivo loss-of-function studies and inactivation of specific protein domains, diagnostic imaging, tumor therapy and treatment for neurodegenerative and infectious diseases. This review will focus on their in vivo applications

For centuries analyses of tissues have depended on sectioning methods. Recent developments of tissue clearing techniques have now opened a segway from studying tissues in 2 dimensions to 3 dimensions. This particular advantage echoes heavily in the field of neuroscience, where in the last several years there has been an active shift towards understanding the complex orchestration of neural circuits. In the past five years, many tissue-clearing protocols have spawned. This is due to varying strength of each clearing protocol to specific applications. However, two main protocols have shown their applicability to a vast number of applications and thus are exponentially being used by a growing number of laboratories. In this review, we focus specifically on two major tissue-clearing method families, derived from the 3DISCO and the CLARITY clearing protocols. Moreover, we provide a “hands-on” description of each tissue clearing protocol and the steps to look out for when deciding to choose a specific tissue clearing protocol. Lastly, we provide perspectives for the development of tissue clearing protocols into the research community in the fields of embryology and cancer.