Fluorescence & Imaging

Buying guide

This page spans more categories than any single one of them, so the price range is the widest on the site. Across the work, listings run from EUR 4 to EUR 244.724. The bottom end is accessories and consumables: a filter cube, a slide holder, a gel dryer part, the small pieces that complete a setup already in place. The top end is the research confocal, a scanning head, laser lines, motorised stage and sensitive detector together, which is where the four and five-figure figures sit. Molecular imagers and complete fluorescence microscopes fall between, closer to the top when they arrive as full systems with camera and filters.

Condition is where this catalogue leans heavily one way. Of the listings, 95 percent are used. For optics that is less of a concern than it sounds: a well-kept objective or a confocal scanner does not degrade the way a moving instrument might, and the saving against new is substantial. What matters more is completeness. A microscope is only as capable as its filter cubes, and an imager only reads the dyes its installed filters allow, so check what a listing actually includes before comparing prices.

Where you have to weigh a used system against a new one, the clear difference is price: used and refurbished units list below new. Warranty is often possible and is arranged in consultation for the specific listing, so that is the place to settle it rather than assuming it from the condition alone. Parts and accessories can be sourced via Questpair, which is what makes buying an incomplete system and completing it a workable route.

Types of Fluorescence & Imaging

Fluorescence and imaging is not a single workflow but a set of related ones, held together by one idea: light in, light out, recorded. The equipment this draws on spans microscopes and confocal systems for looking at cells, molecular imagers and gel documentation systems for reading blots and gels, and the cameras, filters and accessories that make either possible. The sections below group the work by what it is trying to see, because that is what decides the kit.

How do microscopy and confocal systems differ for fluorescence?

A widefield fluorescence microscope floods the whole field with excitation light and reads the emission on a camera. It is fast and simple, and for thin samples, a monolayer of cells, a smear, a section a few microns deep, it is enough. The limit shows up with thickness: out-of-focus light from above and below the plane washes into the image and the contrast collapses.

A confocal answers that by rejecting the out-of-focus light. A pinhole in front of the detector admits only light from the focal plane, so the system can build a clean optical section and, by stepping through the sample, a stack. That is what thick specimens and three-dimensional reconstruction need. The cost is complexity: a scanning head, precise focus control and, usually, laser excitation rather than a lamp. On the marketplace both sit under the microscopy listings, and the accessories, objectives, stages, filter sets, often transfer between them.

The practical decision is sample depth against budget. A lab imaging fixed slides rarely needs the confocal; a lab imaging organoids or whole-mount tissue cannot do without one.

Reading blots and gels: what does molecular imaging need?

Western blot and gel imaging is a separate branch of the same physics. Here the subject is a membrane or a gel carrying bands, and the signal is often faint. The equipment, molecular imagers and gel documentation systems, is built around a sensitive camera, a dark enclosure to keep stray light out, and a choice of excitation. Fluorescent westerns need the right excitation wavelength and emission filter for each dye; chemiluminescent blots need no excitation at all, just a camera patient enough to integrate a weak glow over a long exposure.

Where two steps constrain each other is the dye-to-filter match. A two-colour western only separates cleanly if the imager carries filters that isolate each emission band, and a system bought for one dye set may not read another. This is the kind of dependency a category page for cameras or imagers cannot state, because it only appears once the detector and the chemistry are considered together.

Gel dryers belong to the same bench: once a gel has been imaged, drying preserves it for storage or autoradiography. They are listed here because they sit at the end of this particular sequence, not because they image anything themselves.

What do cameras and accessories add?

The camera is where much of the sensitivity actually lives. A cooled scientific camera on a fluorescence microscope pulls detail out of a dim sample that a standard sensor would lose in its own noise. On the molecular imaging side, the same choice decides whether a faint band registers at all. Among the listings that specify a type, cameras appear both as part of complete systems and on their own, for fitting to an existing stand.

The accessories, objectives, filter cubes, stages, illuminators, are what let one instrument serve more than one assay. A filter set defines which fluorophores a given microscope can read, so adding a cube often matters more than changing the microscope. Buying these second-hand is where the breadth of this catalogue tells.