The inverted fluorescence microscope MF53-N adopts an excellent infinitely far achromatic independent correction optical system, equipped with a long working distance flat field achromatic objective lens and a large field eyepiece. Excellent weak fluorescence imaging, using a rotary fluorescence switching method, can be configured with various fluorescence including UV, V, B, G, Y, R, etc. It can observe common fluorescent dyes such as DAPI, FITC, TRITC, Alexa Fluor series, Cy3 series, etc., and is suitable for CTC detection FRET、 Widely used in fields such as cellular immunity.