Published July 2, 2026 at 3:15 PM
There is a class of observations that are impossible in ordinary light but obvious under UV light. Banknotes issued by central banks carry security features designed to be visible only when illuminated with UV. Traces of bodily fluids on surfaces — blood, saliva, urine, semen — fluoresce when exposed to UV. Genuine antique glass and ceramic objects have patinas that glow under UV in a way modern copies never do. Certain adhesive joints, paints and chemical markers are completely invisible to the naked eye but glow under UV. Being able to switch between white and UV light under a digital microscope is the combination that makes this forensic and authentication work practical.
How UV fluorescence works
UV radiation at 375 nm lies just outside the visible spectrum, on the short-wavelength side. When it strikes certain molecules, it is absorbed and the energy is re-emitted as visible light at longer wavelengths — usually blue, green or yellow. This is the principle of fluorescence. The range of substances that fluoresce under 375 nm illumination is surprisingly large: many proteins, collagen and keratin (skin, hair, nails); certain minerals; paper containing optical brighteners; textiles with detergent residues; printer ink and construction adhesives; and a large number of biological markers and fluorophores.
The phenomenon is very different from ordinary reflection. A surface that looks white in white light may glow bluish under UV because of added optical brighteners; a surface that looks identical in white light may glow completely differently under UV if it contains different chemicals. It is this difference that makes UV microscopy a practical tool.
What the instrument offers
The Dino-Lite AM7115MT-FUW is a 5-megapixel USB digital microscope with two separate sets of LEDs: four white LEDs for normal illumination and four 375 nm UV LEDs for fluorescence excitation. Switching between the two is done with a simple switch — in ten seconds the operator can see how an object looks in white light and how it looks under UV.
An important technical detail: an IR cut filter above 650 nm prevents red and infrared ghosting from the UV LEDs from reaching the camera and interfering with the fluorescence image. In addition, there is an emission barrier filter at 375 nm that blocks reflected UV radiation from reaching the sensor — only the longer-wavelength visible light from fluorescence passes through the filter. Without these two filters, the image would be swamped by UV noise and the fluorescence contrast would be severely degraded.
20–220x magnification: The standard Dino-Lite Edge range. At 20x you get overview images of larger areas (an entire section of a banknote, a coin, a printed item); at 220x you focus on microstructures in materials or individual fiber fluorescence points.
Automatic Magnification Reading (AMR): The instrument knows which magnification it is set to based on the position of the focus wheel, and all measurements are compensated automatically — no manual calibration for each zoom setting.
Interchangeable front caps: The standard cap suits most applications, but special caps for tighter spaces or specific working distances are available.
Where a UV microscope makes a real difference
Banknote detectors and cash handling: ATMs, currency exchange offices, and fast-food chains that handle large volumes of cash. Counterfeit banknotes are often revealed by the absence of UV-visible security printing or by incorrect fluorescence colors.
Antiques and art authentication: Assessment of glass, porcelain, coins, medals, documents and paintings. Genuine antiques have aging patinas that differ from modern copies under UV — often the only reliable distinction when the form and material have been carefully copied.
Forensics and crime analysis: Bodily fluid traces, fiber matching, document crimes (erasures, forged signatures made with different inks), and security marking on stolen property.
Dentistry: Detection of bacterial plaque (certain bacterial plaque stains fluoresce), early detection of caries development beneath sealed surfaces, and checking the quality of fillings.
Food industry: Detection of rodent urine on storage surfaces, checking for cleaning residues (some cleaning agents contain UV markers), and verifying that the UV-C radiation from sterilization lamps actually reaches work surfaces.
Textile industry and laundries: Stain detection, checking for detergent residues, and color discrepancies under UV. Assessment of optical brighteners in fabric production.
Paper conservation: Assessment of a paper’s age, previous repairs and retouching. Modern paper with optical brighteners glows dramatically differently from historical paper without such additives.
Mineralogy and gemology: Many minerals have characteristic fluorescence that helps identify them. Diamonds, calcite, willemite, autunite — all have unique UV patterns.
Electronics inspection: Certain solder residues, flux residues and adhesive mixtures fluoresce. UV inspection is standard in some PCB test lines.
Workshop quality control: Fluorescent penetrant testing (Dye Penetrant Inspection, DPI) — a classic NDT method for detecting hairline cracks in metal by applying a fluorescent liquid and illuminating with UV.
What you get for your money
5-megapixel Edge sensor (2592×1944), 20–220x magnification, 4 white + 4 UV LEDs (375 nm), IR cut filter above 650 nm, emission barrier filter at 375 nm, N3C-D diffuser, Automatic Magnification Reading (AMR), Flexible LED Control (FLC), metal housing, USB 2.0 connection, interchangeable front caps.
At 10,891 kronor, this is an investment that a retail business handling cash, an antiques dealer, a jeweler or an authentication consultancy will recoup within a few jobs. For forensic consultants, the instrument can be written off against the first client assignment. For technical education, it is a remarkable teaching tool — students remember UV fluorescence in a way they never forget.
Read more: Dino-Lite AM7115MT-FUW UV microscope in the store →
