PT - JOURNAL ARTICLE AU - Jonas A Ohlsson AU - Jia Xuan Leong AU - Pernilla H Elander AU - Adrian N Dauphinee AU - Florentine Ballhaus AU - Johan Johansson AU - Mark Lommel AU - Gero Hofmann AU - Staffan Betnér AU - Mats Sandgren AU - Karin Schumacher AU - Peter V Bozhkov AU - Elena A Minina TI - SPIRO – the automated Petri plate imaging platform designed by biologists, for biologists AID - 10.1101/2021.03.15.435343 DP - 2021 Jan 01 TA - bioRxiv PG - 2021.03.15.435343 4099 - http://biorxiv.org/content/early/2021/03/18/2021.03.15.435343.short 4100 - http://biorxiv.org/content/early/2021/03/18/2021.03.15.435343.full AB - The imaging of plant seedlings, fungal mycelia and bacterial colonies grown on Petri plates is commonly used in phenotyping assays, and is typically done manually despite the procedures being time-consuming and laborious. The main reason for this is the still limited availability of existing automated phenotyping tools and facilities. Additionally, constructing a custom-made automated solution is a daunting task for most research groups specializing in biology.Here, we describe SPIRO, the Smart Plate Imaging Robot, an automated platform that acquires time-lapse photos of up to four vertically oriented Petri plates in a single experiment. SPIRO was designed for biologists by biologists; thus its assembly does not require experience in engineering or programming and its operation is sufficiently intuitive to be done without training. SPIRO has a small footprint optimal to fit into standard incubators for plants and microbes and is equipped with an LED light source for imaging in the dark, thus allowing acquisition of photos under optimal growth conditions. SPIRO’s web-based user interface allows setting up experiments and downloading data remotely, without interfering with samples growth. The robots’ 8 MP camera provides excellent image quality suitable for automated image processing, which we demonstrate on the example of two semi-automated assays for analysis of commonly used phenotypic traits: seed germination and root growth.Moreover, the robot can be easily customized for a specific use, as all information about SPIRO, including the models for 3D-printed structural components, control software, and scripts for image analysis are released under permissive open source licenses.Competing Interest StatementThe authors have declared no competing interest.