Contact Us | Carl Zeiss

Zeiss Logo

Education in Microscopy and Digital Imaging

ZEISS Microscopy ¦ Products ¦ Solutions ¦ Support ¦ Online Shop ¦ ZEISS International

Light Sources Spectral Imaging Wavelength Selection Microscope Basics Optical Sectioning Fluorescent Proteins Spinning Disk Superresolution
Zeiss Spinning Disk Microscopy Digital Video Gallery

Human Osteosarcoma Cells with mEmerald-PMP and mRuby-ER

mRuby is a monomeric red fluorescent protein that is especially valuable for imaging purposes. At pH extremes, this protein displays an extraordinary amount of resistance to denaturation. Additionally, mRuby is about 10 times brighter in comparison to EGFP (enhanced green fluorescent protein) when targeted to the endoplasmic reticulum. Peroxisomes and the endoplasmic reticulum are examined in this digital video sequence featuring human osteosarcoma cells (U-2 line) fluorescently tagged with mEmerald fused to a peroxisomal membrane protein targeting signal and mRuby fused to an ER targeting signal.

The green fluorescent protein employed to label peroxisomes, mEmerald, is an improved variant of the enhanced Aequorea derivative EGFP. mEmerald experiences peak excitation at 487 nanometers and peak emission at 509 nanometers. The ER was tagged with mRuby, a monomeric derivative of the tetrameric far-red fluorescent protein eqFP611. Excitation and emission of mRuby peak at 558 and 605 nanometers, respectively.