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The analysis of circulating tumor cells (CTCs) is important for cancer diagnosis and prognosis. Microfluidics has been employed for CTC analysis due to its scaling advantages and high performance. However, pre-analytical methods for CTC sample preparation are often combined with microfluidic platforms because a large sample volume is required to detect extremely rare CTCs. Among pre-analytical methods, Ficoll-Paque[TM], OncoQuick[TM], and RosetteSep[TM] are commonly used to separate cells of interest. To compare their performance, we spiked L3.6pl pancreatic cancer cells into healthy blood samples and then employed each technique to prepare blood samples, followed by using a microfluidic platform to capture and detect L3.6pl cells. We found these three methods have similar performance, though the slight edge of RosetteSep[TM] over Ficoll-Paque[TM] is statistically significant. We also studied the effects of the tumor cell concentrations on the performance of the frequently used Ficoll-Paque[TM] method. Furthermore, we examined the repeatability and variability of each pre-analytical technique and the microfluidics-enabled detection. This study will provide researchers and clinicians with comparative data that can influence the choice of sample preparation method, help estimate Cl'C loss in each pre-analytical method, and correlate the results of clinical studies that employ different techniques. Key words: preanalytical, sample preparation, microfluidics, circulating tumor cells. L'analyse des cellules tumorales circulantes (CTC) est une pierre angulaire du diagnostic et du pronostic du cancer. On recourt a la microfluidique pour l'analyse des CTC en raison des avantages qu'elle offre pour la mise a l'echelle et de sa grande performance. Par ailleurs, les methodes preanalytiques pour la preparation d'echantillons de CTC font souvent appel a des plateformes microfluidiques, car il faut un grand volume d'echantillon pour detecter des CTC extremement rares. Parmi les methodes preanalytiques couramment utilisees pour separer les cellules sanguines d'interet, notons Ficoll-[Paque.sup.MC], [OncoQuick.sup.MC] et [RosetteSep.sup.MC]. Afin de comparer les performances de ces methodes, nous avons additionne de cellules de cancer du pancreas L3,6pl des echantillons de sang sains, puis nous avons utilise les trois methodes pour preparer les echantillons sanguins, que nous avons ensuite soumis a une plateforme microfluidique pour isoler et detecter les cellules L3,6pl. Nos resultats montrent que les performances de ces trois methodes sont similaires, bien que le leger avantage de [RosetteSep.sup.MC] par rapport a Ficoll-[Paque.sup.MC] soit statistiquement significatif. Nous avons egalement etudie les effets des concentrations de cellules tumorales sur la performance de la methode Ficoll-[Paque.sup.MC], qui est la plus frequemment utilisee. En outre, nous avons examine la repetabilite et la variability de chaque methode preanalytique et les caracteristiques de detection que permet d'obtenir la microfluidique. Cette etude fournit aux chercheurs et aux cliniciens des donnees comparatives qui peuvent influencer leur choix de la methode de preparation des echantillons, et permet d'estimer la perte de CTC propre a chaque methode preanalytique et de correler les resultats des etudes cliniques qui utilisent differentes techniques. [Traduit par la Redaction] Mots-cles: preanalytique, preparation d'echantillons, microfluidique, cellules tumorales circulantes., Introduction An important function of human blood is to distribute substances for maintaining homeostasis and protecting the body. Unfortunately, this transport system is exploited by malignant tumor cells during the [...]

Timely and accurate diagnosis is critical for effective healthcare, yet nearly half the global population lacks access to basic diagnostics. Point-of-care (POC) testing offers partial solutions by enabling low-cost, rapid diagnosis at the patient's location. At-home POC devices have the potential to advance preventive care and early disease detection. Nevertheless, effective sample preparation and detection methods are essential for accurate results. This review surveys recent advances in sample preparation and detection methods at POC. The goal is to provide an in-depth understanding of how these technologies can enhance at-home POC devices. Lateral flow assays, nucleic acid tests, and virus detection methods are at the forefront of POC diagnostic technology, offering rapid and sensitive tools for identifying and measuring pathogens, biomarkers, and viral infections. By illuminating cutting-edge research on assay development for POC diagnostics, this review aims to accelerate progress towards widely available, user-friendly, at-home health monitoring tools that empower individuals in personalized healthcare in the future. [ABSTRACT FROM AUTHOR]

Pathogens can be collected from air and detected in samples by many methods. However, merely detecting pathogens does not answer whether they can spread disease. To fully assess health risks from exposure to airborne pathogens, the infectivity of those agents must be assessed. Air samplers which operate by growing particles through water vapor condensation and subsequently collecting them into a liquid medium have proven effective at conserving the viability of microorganisms. We present a study that assessed performance improvement of one such sampler, BioSpot-GEM™, gained by augmenting it with an upstream virtual impactor (VI) designed to concentrate particles in aerosols. We demonstrate that such an integrated unit improved the collection of live Escherichia coli by a median Concentration Factor (CF) of 1.59 and increased the recovery of viable human coronavirus OC43 (HCoV OC43) by a median CF of 12.7 as compared to the sampler without the VI. Our results also show that OC43 can be concentrated in this way without significant loss of infectivity. We further present that the small BioSpot-GEM™ bioaerosol sampler can collect live E. coli at an efficiency comparable to the larger BioSpot-VIVAS™ bioaerosol sampler. Our analyses show potential benefits toward improving the collection of viable pathogens from the air using a more portable water-based condensation air sampler while also highlighting challenges associated with using a VI with concentrated bioaerosols. This work can aid further investigation of VI usage to improve the collection of pathogens from air, ultimately to better characterize health risks associated with airborne pathogen exposures. Copyright © 2024 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

Airborne transmission of infectious (viable) SARS-CoV-2 is increasingly accepted as the primary manner by which the virus is spread from person to person. Risk of exposure to airborne virus is higher in enclosed and poorly ventilated spaces. We present a study focused on air sampling within residences occupied by individuals with COVID-19. Air samplers (BioSpot-VIVAS, VIVAS, and BC-251) were positioned in primary- and secondary-occupancy regions in seven homes. Swab samples were collected from high-touch surfaces. Isolation of SARS-CoV-2 was attempted for samples with virus detectable by RT-qPCR. Viable virus was quantified by plaque assay, and complete virus genome sequences were obtained for selected samples from each sampling day. SARS-CoV-2 was detected in 24 of 125 samples (19.2%) by RT-qPCR and isolated from 14 (11.2%) in cell cultures. It was detected in 80.9% (17/21) and cultured from 61.9% (13/21) of air samples collected using water condensation samplers, compared to swab samples which had a RT-qPCR detection rate of 10.5% (4/38) and virus isolation rate of 2.63% (1/38). No statistically significant differences existed in the likelihood of virus detection by RT-qPCR or amount of infectious virus in the air between areas of primary and secondary occupancy within residences. Our work provides information about the presence of SARS-CoV-2 in the air within homes of individuals with COVID-19. Information herein can help individuals make informed decisions about personal exposure risks when sharing indoor spaces with infected individuals isolating at home and further inform health departments and the public about SARS-CoV-2 exposure risks within residences. [ABSTRACT FROM AUTHOR]

Enzymes and membrane protein receptors represent almost three-quarters of all current drug targets. As a result, it would be beneficial to have a platform to produce them in a high-throughput format for drug screening. We have developed a miniaturized fluid array device for cell-free protein synthesis, and the device was exploited to produce both soluble and membrane proteins. Two membrane-associated proteins, bacteriorhodopsin and ApoA lipoprotein, were coexpressed in an expression medium in the presence of lipids. Simultaneous expression of ApoA lipoprotein enhanced the solubility of bacteriorhodopsin and would facilitate functional studies. In addition, the device was employed to produce two enzymes, luciferase and [beta]-lactamase, both of which were demonstrated to be compatible with enzyme inhibition assays. [beta]-lactamase, a drug target associated with antibiotic resistance, was further used to show the capability of the device for drug screening. [beta]-Lactamase was synthesized in the 96 units of the device and then assayed by a range of concentrations of four mock drug compounds without harvesting and purification. The inhibitory effects of these compounds on [beta]-lactamase were measured in a parallel format, and the degree in their drug effectiveness agreed well with the data in the literature. This work demonstrated the feasibility of the use of the fluid array device and cell-free protein expression for drug screening, with advantages in less reagent consumption, shorter analysis time, and higher throughput. 10.1021/ac1015479