Core-Shell Beads as Microreactors for Phylogrouping of E. coli Strains

Abstract

Multiplex polymerase chain reaction (PCR) is an effective tool for simultaneous detection of target genes. Nevertheless, their use has been restricted due to the intrinsic interference between primer pairs. Performing several single PCRs in an array format instead of a multiplex PCR is a simple way to overcome this obstacle. However, there are still major technical challenges in designing a new generation of single PCR microreactors with a small sample volume, rapid thermal cycling, and no evaporation during amplification. We report a simple and robust core-shell bead array for a series of single amplifications. Four core-shell beads with a polymer coating and PCR mixture were synthesized using liquid marble formation and subsequent photo polymerization. Each bead can detect one target gene. We constructed a customised system for thermal cycling of these core-shell beads. Phylogrouping of the E. coli strains was carried out based on the fluorescent signal of the core-shell beads. This platform can be a promising alternative for multiplex nucleic acid analyses due to its simplicity and high throughput. The platform reported here also reduces the cycling time and avoids evaporation as well as contamination of the sample during the amplification process.

A Portable Device for LAMP Based Detection of SARS-CoV-2

“…The images were processed with ImageJ software to quantitatively evaluate the variation in fluorescent intensity with respect to time. The numerical equivalent values of the fluorescence were offset corrected and normalized using the equation [10,[19][20][21].…”

Phylogrouping and characterization of Escherichia coli isolated from colonic biopsies and fecal samples of patients with flare of inflammatory bowel disease in Iran

“…Among typing methods applied for characterization of E. coli strains, such as pulsed-field gel electrophoresis (PFGE), enterobacterial repetitive intergenic consensus sequence (ERIC)-PCR, randomly amplified polymorphic DNA (RAPD), ribotyping, multiplex phylogrouping PCR has been widely employed because of its simplicity and rapidity ( 20 – 22 ). Phylogrouping technique is also useful for genetic structure analysis of E. coli populations, classification of extraintestinal pathogenic and commensal strains, and also host-source relationships ( 23 ).…”

Formation of core–shell droplets for the encapsulation of liquid contents

“…TMPTMA is commonly used in dentistry and does not show any evidence of toxic effects. The TMPTMA solution was prepared at a concentration of 98 mol% according to a previous report, and thus maintain the spherical shape and stable dimension of the core-shell particle after polymerization (Gorgannezhad et al 2020;. Next, the core droplets delivered into the second junction are encapsulated by the shell liquid to generate a core-shell droplet in a continuous phase of 50% glycerol solution.…”