Extended Data Fig. 1: CRISPRi induction, sorting schema, and construction of CASA (CRISPR Activity Screen Analysis), a generative model of CRE activity.

a, Induction of CRISPRi linked to BFP via doxycycline shows robust activation. b, Example sorting strategy showing detection of a target transcript (GATA1) amplified with Alexa-647 conjugated hairpins, and a housekeeping transcript (TBP) amplified with Alexa-488 conjugated hairpins. The top and bottom 10% of 647:488 normalized ratio are differentially sorted. c, The generative process underlying CASA (CRISPR Activity Screen Analysis) described as a plate model, explicit statistical parameterization, and variable definitions. Shaded and unshaded circles indicate observed and latent variables, respectively. The variable W corresponds to the set of windows tested, while each N_w arises from the set of sgRNAs considered at the w^th window.