The influence of transposable elements on animal colouration.

Transposable elements (TEs) are mobile genetic sequences present within host genomes. TEs can contribute to the evolution of host traits, since transposition is mutagenic and TEs often contain host regulatory and protein coding sequences. We review cases where TEs influence animal colouration, reporting major patterns and outstanding questions. TE-induced colouration phenotypes typically arise via introduction of novel regulatory sequences and splice sites, affecting pigment cell development or pigment synthesis. We discuss if particular TE types may be more frequently involved in the evolution of colour variation in animals, given that examples involving long terminal repeat (LTR) elements appear to dominate. Currently, examples of TE-induced colouration phenotypes in animals mainly concern model and domesticated insect and mammal species. However, several influential recent examples, coupled with increases in genome sequencing, suggest cases reported from wild species will increase considerably.

Earl Grey: A Fully Automated User-Friendly Transposable Element Annotation and Analysis Pipeline.

Transposable elements (TEs) are major components of eukaryotic genomes and are implicated in a range of evolutionary processes. Yet, TE annotation and characterization remain challenging, particularly for nonspecialists, since existing pipelines are typically complicated to install, run, and extract data from. Current methods of automated TE annotation are also subject to issues that reduce overall quality, particularly (i) fragmented and overlapping TE annotations, leading to erroneous estimates of TE count and coverage, and (ii) repeat models represented by short sections of total TE length, with poor capture of 5' and 3' ends. To address these issues, we present Earl Grey, a fully automated TE annotation pipeline designed for user-friendly curation and annotation of TEs in eukaryotic genome assemblies. Using nine simulated genomes and an annotation of Drosophila melanogaster, we show that Earl Grey outperforms current widely used TE annotation methodologies in ameliorating the issues mentioned above while scoring highly in benchmarking for TE annotation and classification and being robust across genomic contexts. Earl Grey provides a comprehensive and fully automated TE annotation toolkit that provides researchers with paper-ready summary figures and outputs in standard formats compatible with other bioinformatics tools. Earl Grey has a modular format, with great scope for the inclusion of additional modules focused on further quality control and tailored analyses in future releases.

Database derived from an electronic medical record-based surveillance network of US emergency department patients with acute respiratory illness.

BACKGROUND: For surveillance of episodic illness, the emergency department (ED) represents one of the largest interfaces for generalizable data about segments of the US public experiencing a need for unscheduled care. This protocol manuscript describes the development and operation of a national network linking symptom, clinical, laboratory and disposition data that provides a public database dedicated to the surveillance of acute respiratory infections (ARIs) in EDs. METHODS: The Respiratory Virus Laboratory Emergency Department Network Surveillance (RESP-LENS) network includes 26 academic investigators, from 24 sites, with 91 hospitals, and the Centers for Disease Control and Prevention (CDC) to survey viral infections. All data originate from electronic medical records (EMRs) accessed by structured query language (SQL) coding. Each Tuesday, data are imported into the standard data form for ARI visits that occurred the prior week (termed the index file); outcomes at 30 days and ED volume are also recorded. Up to 325 data fields can be populated for each case. Data are transferred from sites into an encrypted Google Cloud Platform, then programmatically checked for compliance, parsed, and aggregated into a central database housed on a second cloud platform prior to transfer to CDC. RESULTS: As of August, 2023, the network has reported data on over 870,000 ARI cases selected from approximately 5.2 million ED encounters. Post-contracting challenges to network execution have included local shifts in testing policies and platforms, delays in ICD-10 coding to detect ARI cases, and site-level personnel turnover. The network is addressing these challenges and is poised to begin streaming weekly data for dissemination. CONCLUSIONS: The RESP-LENS network provides a weekly updated database that is a public health resource to survey the epidemiology, viral causes, and outcomes of ED patients with acute respiratory infections.

Prevalence of Chlamydia trachomatis Infection in Young Women and Associated Predictors.

BACKGROUND: Chlamydia trachomatis (CT) infection remains highly prevalent, and young women are disproportionately affected. Most CT-infected women are asymptomatic, and their infection often goes unrecognized and untreated. We hypothesized that testing for active CT infection with molecular diagnostics and obtaining a reported history of CT infection underestimate the prevalence of current and past CT infection, and incorporating serum CT antibody testing in addition to these other prevalence measures would generate more accurate estimates of the prevalence of CT infection in asymptomatic young women. METHODS: We enrolled 362 asymptomatic women aged 16 to 29 years at 4 different clinical settings in Birmingham, AL, between August 2016 and January 2020 and determined the prevalence of CT infection based on having 1 or more of the following prevalence measures: an active urogenital CT infection based on molecular testing, reported prior CT infection, and/or being CT seropositive. Multivariable regression analysis was used to determine predictors of the prevalence of CT infection after adjustment for participant characteristics. RESULTS: The prevalence of CT infection was 67.7% (95% confidence interval, 62.6%-72.5%). Addition of CT antibody testing to the other individual prevalence measures more than doubled the CT infection prevalence. Non-Hispanic Black race, reported prior gonorrhea, and reported prior trichomoniasis predicted a higher prevalence of CT infection. CONCLUSIONS: More than half of women were unaware of ever having CT infection, suggesting many were at risk for CT-associated reproductive complications. These data reinforce the need to adhere to chlamydia screening guidelines and to increase screening coverage in those at risk.

Horizontal transfer and subsequent explosive expansion of a DNA transposon in sea kraits (Laticauda).

Transposable elements (TEs) are self-replicating genetic sequences and are often described as important 'drivers of evolution'. This driving force is because TEs promote genomic novelty by enabling rearrangement, and through exaptation as coding and regulatory elements. However, most TE insertions potentially lead to neutral or harmful outcomes, therefore host genomes have evolved machinery to suppress TE expansion. Through horizontal transposon transfer (HTT) TEs can colonize new genomes, and since new hosts may not be able to regulate subsequent replication, these TEs may proliferate rapidly. Here, we describe HTT of the Harbinger-Snek DNA transposon into sea kraits (Laticauda), and its subsequent explosive expansion within Laticauda genomes. This HTT occurred following the divergence of Laticauda from terrestrial Australian elapids approximately 15-25 Mya. This has resulted in numerous insertions into introns and regulatory regions, with some insertions into exons which appear to have altered UTRs or added sequence to coding exons. Harbinger-Snek has rapidly expanded to make up 8-12% of Laticauda spp. genomes; this is the fastest known expansion of TEs in amniotes following HTT. Genomic changes caused by this rapid expansion may have contributed to adaptation to the amphibious-marine habitat.

Emergency Medicine Interest Groups.

Emergency Medicine Interest Groups (EMIGs) serve as a bountiful resource for students interested in pursuing a career in Emergency Medicine (EM). In this article we elaborate on how medical students can get involved as members in an EMIG, discuss opportunities for leadership through these groups, detail how to make the most out of the EMIG (including a listing of important lectures, workshops/labs and opportunities for growth and advancement), provide a framework for how to institute a new EMIG when one does not exist, and discuss considerations for international EMIG groups.

High Prevalence of Hepatitis C Infection Among Adult Patients at Four Urban Emergency Departments - Birmingham, Oakland, Baltimore, and Boston, 2015-2017.

Identifying persons with hepatitis C virus (HCV) infection has become an urgent public health challenge because of increasing HCV-related morbidity and mortality, low rates of awareness among infected persons, and the advent of curative therapies (1). Since 2012, CDC has recommended testing of all persons born during 1945-1965 (baby boomers) for identification of chronic HCV infection (1); urban emergency departments (EDs) are well positioned venues for detecting HCV infection among these persons. The United States has witnessed an unprecedented opioid overdose epidemic since 2013 that derives primarily from commonly injected illicit opioids (e.g., heroin and fentanyl) (2). This injection drug use behavior has led to an increase in HCV infections among persons who inject drugs and heightened concern about increases in human immunodeficiency virus (HIV) and HCV infection within communities disproportionately affected by the opioid crisis (3,4). However, targeted strategies for identifying HCV infection among persons who inject drugs is challenging (5,6). During 2015-2016, EDs at the University of Alabama at Birmingham; Highland Hospital, Oakland, California; Johns Hopkins Hospital, Baltimore, Maryland; and Boston University Medical Center, Massachusetts, adopted opt-out (i.e., patients can implicitly accept or explicitly decline testing), universal hepatitis C screening for all adult patients. ED staff members offered HCV antibody (anti-HCV) screening to patients who were unaware of their status.* During similar observation periods at each site, ED staff members tested 14,252 patients and identified an overall 9.2% prevalence of positive results for anti-HCV among the adult patient population. Among the 1945-1965 birth cohort, prevalence of positive results for anti-HCV (13.9%) was significantly higher among non-Hispanic blacks (blacks) (16.0%) than among non-Hispanic whites (whites) (12.2%) (p<0.001). Among persons born after 1965, overall prevalence of positive results for anti-HCV was 6.7% and was significantly higher among whites (15.3%) than among blacks (3.2%) (p<0.001). These findings highlight age-associated differences in racial/ethnic prevalences and the potential for ED venues and opt-out, universal testing strategies to improve HCV infection awareness and surveillance for hard-to-reach populations. This opt-out, universal testing approach is supported by new recommendations for hepatitis C screening at least once in a lifetime for all adults aged ≥18 years, except in settings where the prevalence of positive results for HCV infection is <0.1% (7).

Predictors of linkage to care for a nontargeted emergency department hepatitis C screening program.

OBJECTIVE: We implemented a nontargeted, opt-out HCV testing and linkage to care (LTC) program in an academic tertiary care emergency department (ED). Despite research showing the critical role of ED-based HCV testing programs, predictors of LTC have not been defined for patients identified through the nontargeted ED testing strategy. In order to optimize health outcomes for patients with HCV, we sought to identify predictors of LTC failure. METHODS: This was a retrospective cohort study of adult patients who were tested for HCV in the ED between August 2015 and September 2018 and were confirmed to have chronic HCV infection through RNA testing. We used logistic regression to assess the relationship between candidate predictors and the primary outcome, LTC failure, which was defined as a patient not being seen by an HCV treating provider after discharge from the ED. RESULTS: Of 53,297 patients tested, 1,674 (3.1%) had HCV on confirmatory testing, and 355 (21%) linked to care. Predictors of LTC failure included younger age (OR 0.96, 95% CI 0.95-0.97), white race (OR 1.65, 95% CI 1.23-2.22), homelessness (OR 1.91, 95% CI 1.19-3.08), substance use (OR 1.77, 95% CI 1.34-2.34), and comorbid psychiatric illness (OR 2.16, 95% CI 1.59-2.94). Patients with significant medical comorbidities (OR 0.57, 95% CI 0.41-0.78) or HIV co-infection (OR 0.11, 95% CI 0.03-0.46) were less likely to experience LTC failure. CONCLUSIONS: One in five HCV-infected patients identified by ED-based nontargeted testing successfully linked to an HCV treating provider. Predictors of LTC failure may guide the development of targeted interventions to improve LTC success.

Human Immunodeficiency Virus Risk Factors and Beliefs Reported by Families Presenting to a Pediatric Emergency Department.

OBJECTIVES: Adolescents are at greater risk for acquiring human immunodeficiency virus (HIV) due to increased risk behaviors. Parental influence is known to reduce adolescent risk behaviors. We compared HIV risk behaviors reported by adolescents to parents' perception of adolescent risky behavior engagement. We also examined participants' knowledge of HIV transmission and testing preferences. METHODS: Participants included English-speaking adolescents and parents presenting to a pediatric emergency department. Participants were interviewed separately in private. Modeled after existing instruments, "adolescent" and "parent" questionnaires included multiple choices items, Likert-type scales, and standard yes/no and true/false options. Data were analyzed using a κ statistic and observed agreement to measure discordance between adolescent and parent responses. RESULTS: Participants included 126 adolescents and 110 parents. Many adolescents reported ever having sex (61%), of which 32% reported always practicing safe sex. Comparative analysis revealed low agreement between adolescents' risk behaviors and parents' perception of risk behavior engagement by youth. Discordance concerning tobacco use was greatest (κ = 0.13), followed by drug use (κ = 0.19) and ever having sex (κ= 0.19), and alcohol use (κ= 0.22). There was also poor agreement regarding HIV transmission knowledge (ie, oral sex; κ = 0.16). Participants shared strong agreement regarding parental support for adolescent interest in HIV testing (95.5%). CONCLUSIONS: Parents are mostly unaware of adolescents' broad risk behaviors. Participants' knowledge of HIV transmission is limited. Adolescents and parents shared strong agreement regarding HIV testing preferences. Multidimensional HIV prevention strategies aiming to decrease adolescent risk behaviors, increase parental involvement, and improve adolescent and parental knowledge of HIV transmission are needed.

Continuum of Care for Hepatitis C Virus Among Patients Diagnosed in the Emergency Department Setting.

BACKGROUND.: Urban emergency departments (EDs) seem to be able to detect new hepatitis C virus (HCV) infections at a high rate, but it is unknown the extent to which individuals screened in the ED can progress to treatment and cure. We evaluate the HCV Continuum of Care for patients identified with HCV in 2 urban EDs, and consider the results in the context of outcomes from ambulatory screening venues where 2%-10% of chronically infected patients are treated. METHODS.: This is a multicenter, retrospective cohort study of 2 ED HCV screening programs. Patients who screened HCV antibody reactive between 1 May and 31 October 2014 were followed for up to 18 months. The main outcome was the absolute number and proportion of eligible patients who completed each stage of the HCV Continuum of Care. RESULTS.: A total of 3704 ED patients were estimated to have undiagnosed HCV infection, and screening identified 532 (14.4%) HCV antibody-reactive patients. Of the 532 HCV antibody-reactive patients, 435 completed viral load testing (82%), of whom 301 (69%) were chronically infected. Of the 301 chronically infected patients, 158 had follow-up arranged (52%), of whom 97 attended their appointment (61%). Of these 97, 24 began treatment (25%), and 19 of these 24 achieved sustained virological response (79%). CONCLUSIONS.: Urban EDs serve patients with poor access to preventive care services who have a high prevalence of HCV infection. Because ED patients identified with HCV infection can progress to treatment and cure with rates comparable to ambulatory care settings, implementation of ED HCV screening should be expanded.

Emergency Department Screening for Hepatitis C Virus: Geographic Reach and Spatial Clustering in Central Alabama.

Hepatitis C virus (HCV) infection is a growing problem, disproportionately affecting those born between 1945 and 1965. Here, we demonstrate the wide geographic reach and surveillance potential of emergency department-based screening and identify areas of elevated HCV infection in central Alabama that were socioeconomically disadvantaged compared with surrounding communities.

Unrecognized chronic hepatitis C virus infection among baby boomers in the emergency department.

UNLABELLED: The Centers for Disease Control and Prevention and U.S. Preventive Services Task Force have highlighted public screening as an essential strategy for increasing hepatitis C virus (HCV) detection in persons born between 1945 and 1965 ("baby boomers"). Because earlier HCV screening efforts have not targeted emergency department (ED) baby boomer patients, we describe early experience with integrated opt-out HCV antibody (Ab) screening of medically stable baby boomers presenting to an urban academic ED. We performed HCV Ab testing 24 hours per day and confirmed positive test results using polymerase chain reaction (PCR). The primary outcome was prevalence of unrecognized HCV infection. Among 2,325 unique HCV-unaware baby boomers, 289 (12.7%) opted out of HCV screening. We performed HCV Ab tests on 1,529 individuals, of which 170 (11.1%) were reactive. Among Ab reactive cases, follow-up PCR was performed on 150 (88.2%), of which 102 (68.0%) were confirmed RNA positive. HCV Ab reactivity was more likely in males compared to females (14.7% vs. 7.4%; P<0.001), African Americans compared to whites (13.3% vs. 8.8%; P=0.010), and underinsured/ uninsured patients compared to insured patients (16.8%/16.9% vs. 5.0%; P=0.001). Linkage-to-care service activities were recorded for 100 of the 102 confirmed cases. Overall, 54 (54%) RNA-positive individuals were successfully contacted by phone within five call-back attempts. We confirmed initial follow-up appointments for 38 (70.4%) RNA-positive individuals successfully contacted, and 21 (55.3%) individuals with confirmed appointments attended their initial visit with a liver specialist; 3 (7.9%) are awaiting an upcoming scheduled appointment. CONCLUSION: We observed high prevalence of unrecognized chronic HCV infection in this series of baby boomers presenting to the ED, highlighting the ED as an important venue for high-impact HCV screening and linkage to care.

Defining a new diagnostic assessment parameter for wound care: Elevated protease activity, an indicator of nonhealing, for targeted protease-modulating treatment.

It is widely accepted that elevated protease activity (EPA) in chronic wounds impedes healing. However, little progress has occurred in quantifying the level of protease activity that is detrimental for healing. The aim of this study was to determine the relationship between inflammatory protease activity and wound healing status, and to establish the level of EPA above which human neutrophil-derived elastase (HNE) and matrix metalloproteases (MMP) activities correlate with nonhealing wounds. Chronic wound swab samples (n = 290) were collected from four wound centers across the USA to measure HNE and MMP activity. Healing status was determined according to percentage reduction in wound area over the previous 2-4 weeks; this was available for 211 wounds. Association between protease activity and nonhealing wounds was determined by receiver operating characteristic analysis (ROC), a statistical technique used for visualizing and analyzing the performance of diagnostic tests. ROC analysis showed that area under the curve (AUC) for HNE were 0.69 for all wounds and 0.78 for wounds with the most reliable wound trajectory information, respectively. For MMP, the corresponding AUC values were 0.70 and 0.82. Analysis suggested that chronic wounds having values of HNE >5 and/or MMP ≥13, should be considered wound healing impaired. EPA is indicative of nonhealing wounds. Use of a diagnostic test to detect EPA in clinical practice could enable clinicians to identify wounds that are nonhealing, thus enabling targeted treatment with protease modulating therapies.

National estimates of healthcare utilization by individuals with hepatitis C virus infection in the United States.

BACKGROUND: Hepatitis C virus (HCV) infection is a major public health problem in the United States. Although prior studies have evaluated the HCV-related healthcare burden, these studies examined a single treatment setting and did not account for the growing "baby boomer" population (individuals born during 1945-1965). METHODS: Data from the National Ambulatory Medical Care Survey, the National Hospital Ambulatory Medical Care Survey, and the Nationwide Inpatient Sample were analyzed. We sought to characterize healthcare utilization by individuals infected with HCV in the United States, examining adult (≥18 years) outpatient, emergency department (ED), and inpatient visits among individuals with HCV diagnosis for the period 2001-2010. Key subgroups included persons born before 1945 (older), between 1945 and 1965 (baby boomer), and after 1965 (younger). RESULTS: Individuals with HCV infection were responsible for >2.3 million outpatient, 73 000 ED, and 475 000 inpatient visits annually. Persons in the baby boomer cohort accounted for 72.5%, 67.6%, and 70.7% of care episodes in these settings, respectively. Whereas the number of outpatient visits remained stable during the study period, inpatient admissions among HCV-infected baby boomers increased by >60%. Inpatient stays totaled 2.8 million days and cost >$15 billion annually. Nonwhites, uninsured individuals, and individuals receiving publicly funded health insurance were disproportionately affected in all healthcare settings. CONCLUSIONS: Individuals with HCV infection are large users of outpatient, ED, and inpatient health services. Resource use is highest and increasing in the baby boomer generation. These observations illuminate the public health burden of HCV infection in the United States.

Rapid three-dimensional isotropic imaging of living cells using Bessel beam plane illumination.

A key challenge when imaging living cells is how to noninvasively extract the most spatiotemporal information possible. Unlike popular wide-field and confocal methods, plane-illumination microscopy limits excitation to the information-rich vicinity of the focal plane, providing effective optical sectioning and high speed while minimizing out-of-focus background and premature photobleaching. Here we used scanned Bessel beams in conjunction with structured illumination and/or two-photon excitation to create thinner light sheets (<0.5 µm) better suited to three-dimensional (3D) subcellular imaging. As demonstrated by imaging the dynamics of mitochondria, filopodia, membrane ruffles, intracellular vesicles and mitotic chromosomes in live cells, the microscope currently offers 3D isotropic resolution down to ∼0.3 µm, speeds up to nearly 200 image planes per second and the ability to noninvasively acquire hundreds of 3D data volumes from single living cells encompassing tens of thousands of image frames.

Multiple horizontal transfer events of a DNA transposon into turtles, fishes, and a frog.

Horizontal transfer of transposable elements (HTT) has been reported across many species and the impact of such events on genome structure and function has been well described. However, few studies have focused on reptilian genomes, especially HTT events in Testudines (turtles). Here, as a consequence of investigating the repetitive content of Malaclemys terrapin terrapin (Diamondback turtle) we found a high similarity DNA transposon, annotated in RepBase as hAT-6_XT, shared between other turtle species, ray-finned fishes, and a frog. hAT-6_XT was notably absent in reptilian taxa closely related to turtles, such as crocodiles and birds. Successful invasion of DNA transposons into new genomes requires the conservation of specific residues in the encoded transposase, and through structural analysis, these residues were identified indicating some retention of functional transposition activity. We document six recent independent HTT events of a DNA transposon in turtles, which are known to have a low genomic evolutionary rate and ancient repeats.

Compartmentalized Cytoplasmic Flows Direct Protein Transport to the Cell's Leading Edge.

Inside the cell, proteins essential for signaling, morphogenesis, and migration navigate complex pathways, typically via vesicular trafficking or microtubule-driven mechanisms 1-3 . However, the process by which soluble cytoskeletal monomers maneuver through the cytoplasm's ever-changing environment to reach their destinations without using these pathways remains unknown. 4-6 Here, we show that actin cytoskeletal treadmilling leads to the formation of a semi-permeable actin-myosin barrier, creating a specialized compartment separated from the rest of the cell body that directs proteins toward the cell edge by advection, diffusion facilitated by fluid flow. Contraction at this barrier generates a molecularly non-specific fluid flow that transports actin, actin-binding proteins, adhesion proteins, and even inert proteins forward. The local curvature of the barrier specifically targets these proteins toward protruding edges of the leading edge, sites of new filament growth, effectively coordinating protein distribution with cellular dynamics. Outside this compartment, diffusion remains the primary mode of protein transport, contrasting sharply with the directed advection within. This discovery reveals a novel protein transport mechanism that redefines the front of the cell as a pseudo-organelle, actively orchestrating protein mobilization for cellular front activities such as protrusion and adhesion. By elucidating a new model of protein dynamics at the cellular front, this work contributes a critical piece to the puzzle of how cells adapt their internal structures for targeted and rapid response to extracellular cues. The findings challenge the current understanding of intracellular transport, suggesting that cells possess highly specialized and previously unrecognized organizational strategies for managing protein distribution efficiently, providing a new framework for understanding the cellular architecture's role in rapid response and adaptation to environmental changes.

A chromosome-level assembly of the seed beetle Callosobruchus maculatus genome with annotation of its repetitive elements.

Callosobruchus maculatus is a major agricultural pest of legume crops worldwide and an established model system in ecology and evolution. Yet, current molecular biological resources for this species are limited. Here, we employ Hi-C sequencing to generate a greatly improved genome assembly and we annotate its repetitive elements in a dedicated in-depth effort where we manually curate and classify the most abundant unclassified repeat subfamilies. We present a scaffolded chromosome-level assembly, which is 1.01 Gb in total length with 86% being contained within the 9 autosomes and the X chromosome. Repetitive sequences accounted for 70% of the total assembly. DNA transposons covered 18% of the genome, with the most abundant superfamily being Tc1-Mariner (9.75% of the genome). This new chromosome-level genome assembly of C. maculatus will enable future genetic and evolutionary studies not only of this important species but of beetles more generally.

Coumarin as a general switching auxiliary to prepare photochromic and spontaneously blinking fluorophores.

Single-molecule localization microscopy (SMLM) uses activatable or switchable fluorophores to create non-diffraction limited maps of molecular location in biological samples. Despite the utility of this imaging technique, the portfolio of appropriate labels for SMLM remains limited. Here, we describe a general strategy for the construction of "glitter bomb" labels by simply combining rhodamine and coumarin dyes though an amide bond. Condensation of the ortho-carboxyl group on the pendant phenyl ring of rhodamine dyes with a 7-aminocoumarin yields photochromic or spontaneously blinking fluorophores depending on the parent rhodamine structure. We apply this strategy to prepare labels useful super-resolution experiments in fixed cells using different attachment techniques. This general glitter bomb strategy should lead to improved labels for SMLM, ultimately enabling the creation of detailed molecular maps in biological samples.

Using Single Molecule Imaging to Explore Intracellular Heterogeneity.

Despite more than 100 years of study, it is unclear if the movement of proteins inside the cell is best described as a mosh pit or an exquisitely choreographed dance. Recent studies suggest the latter. Local interactions induce molecular condensates such as liquid-liquid phase separations (LLPSs) or non-liquid, functionally significant molecular aggregates, including synaptic densities, nucleoli, and Amyloid fibrils. Molecular condensates trigger intracellular signaling and drive processes ranging from gene expression to cell division. However, the descriptions of condensates tend to be qualitative and correlative. Here, we indicate how single-molecule imaging and analyses can be applied to quantify condensates. We discuss the pros and cons of different techniques for measuring differences between transient molecular behaviors inside and outside condensates. Finally, we offer suggestions for how imaging and analyses from different time and space regimes can be combined to identify molecular behaviors indicative of condensates within the dynamic high-density intracellular environment.