View GFP at its best with a Dark Reader

The optical performance of Dark Reader technology is perhaps most spectacular when viewing Green Fluorescent Proteins. The new generation of red-shifted GFPs have excitation and emission properties that are very well suited for viewing with Dark Reader devices. For example, EGFP (ex/em = 488/507 nm) can be detected, by eye, down to concentrations of less than 100 pM. ECFP, EYFP and DsRed are also highly fluorescent under Dark Reader light.

Image of EGFP excitation spectra

X-Ray Vision!

GFP in tubes

The benefit of using Dark Reader light rather than UV light for viewing GFPs is particularly pronounced when viewing GFPs contained within a glass or plastic unit such as a gel apparatus, Petri dish or test-tube.

Image of tubes in a row that fluoresce green and red

GFP in bacterial colonies

Picking fluorescently-transformed bacterial colonies has never been easier!

Image of fluorescent bacterial colonies under DR handheld lamp
Image of fluorscent transgenic flower

GFP in plants

The Dark Reader Hand Lamp is proving very popular for the detection of GFP expression in plants. Dr. Anton Callaway at North Carolina State University provided the accompanying photograph of Nicotiana benthamiana plants inoculated with turnip vein-clearing tobamovirus engineered to express an endoplasmic reticulum-localized form of EGFP.

The photograph was taken 6 days post-inoculation using a DR Hand Lamp. The green fluorescent spots (against a background of red chlorophyll fluorescence) show the expanding foci of virus-infected cells.

Also, a group at a leading agricultural biotech company reports successfully using the Dark Reader Hand Lamp to detect EGFP transgene expression in Aridopsis thaliana.

RFP in transgenics

Not all transgenics have to be for serious research! Zebrafish expressing red, green and yellow fluorescent proteins have recently been introduced to the home-aquarium market as GloFish™. And using a Dark Reader makes for stunning viewing.

The 550 nm excitation maximum of RFP may seem to put this particular fluorophor outside the range of the blue light Dark Reader. Clearly, this is not the case. The reason is evident from a more detailed consideration of the RFP excitation spectrum which reveals substantial excitation between 400 – 500 nm.

More Transgenic Examples

Fluorescent leaves, corn, roots, sheep or silkworm cocoons. The potential applications are unlimited.