X cite led illumination system

Fluorescently labelled magnetic microparticles were placed in an optical-bottom 96-well plates (Nunc, Thermo Fisher Scientific, Waltham, MA), and placed on a 96-well neodymium magnet array for 3 s to pull microparticles down to the glass surface. An IX83 inverted microscope (Olympus, Tokyo, Japan), equipped with ZeroDrift IX3-ZDC2 continuous focus, was used to measure samples with bright-field illumination from a pE-100 LED (CoolLED, Andover, UK) and epifluorescence excitation light produced by an X-Cite LED illumination system (Excelitas, Wheeling, IL) passing through a Cy3 Olympus dichroic filter cube set (Edmond Optics, Barrington, NJ). Images were acquired through a 20x air objective (UPlanXApo, NA=0·80, Olympus) and recorded on a scientific CMOS PCO.panda camera (PCO, Kelheim, Germany). MetaMorph software (Molecular Devices, San Jose, CA) coordinated imaging measurements, directing a ProScan III xy-stage (Prior Scientific Instruments, Cambridge, UK) to acquire one bright-field image (100 ms, 1·3% LED power) and one (or two) fluorescence image(s) (10 and 100 ms, 25% LED power) at 9 positions within each 96-well. Images were analysed as described previously.²⁰ (link)