Olympus UApo N 340 40x Oil Immersion Apochromat Objective (NA 1.35, UV, Infinity)

The Olympus UApo N 340 40× Oil Immersion Apochromat Objective (NA 1.35) is a UV-optimized apochromat oil immersion objective specifically engineered for high-transmission imaging at 340nm — the excitation wavelength of fura-2, the most widely used ratiometric calcium indicator — delivering exceptional UV fluorescence performance for calcium imaging, ratiometric dye applications, and any workflow requiring high-quality UV excitation through the visible spectrum.

• 🔬 High UV transmission at 340nm — the defining feature of the UApo N 340 series; optimized for maximum light transmission at 340nm, the excitation wavelength of fura-2 and indo-1 for ratiometric calcium imaging
• 🧪 NA 1.35 oil immersion at 40× — high numerical aperture for excellent fluorescence light collection and resolution, maximizing signal from UV-excited fluorophores where photon budget is critical
• 🌟 Apochromat correction (UApo N) — high-level chromatic aberration correction across the UV-visible spectrum for accurate multi-channel imaging combining UV-excited and visible fluorophores
• 📏 Working distance: 0.1mm — optimized for standard coverslip imaging with RMS thread mount
• ♾️ Infinity-corrected, RMS thread — compatible with Olympus BX, CX, and IX series microscopes
• 🇯🇵 Olympus quality, made in Japan — precision optical construction for consistent, high-efficiency UV and visible light transmission
• ✅ New — part number N4274000

🔧 Product Description

The Olympus UApo N 340 40× is a purpose-built UV apochromat objective designed around the specific requirements of fura-2 ratiometric calcium imaging — one of the most demanding UV fluorescence applications in cell biology. Fura-2 requires excitation at two UV wavelengths (340nm and 380nm) with the ratio of emission intensities used to calculate intracellular calcium concentration. This ratiometric approach demands an objective with high, consistent UV transmission at both excitation wavelengths, and the UApo N 340 is specifically optimized to deliver this performance. Standard fluorite and apochromat objectives designed for visible light imaging have significantly reduced transmission below 380nm, making them unsuitable for fura-2 ratiometric imaging where accurate 340nm excitation is essential. The UApo N 340 series addresses this by using optical glass with high UV transmission, ensuring that the 340nm excitation beam reaches the specimen with sufficient intensity for accurate ratiometric calcium measurements. At NA 1.35 with oil immersion, this objective also provides excellent fluorescence light collection efficiency — critical for UV fluorescence applications where the photon budget is inherently limited by UV excitation intensity and fluorophore brightness. Compatible with Olympus BX, CX, and IX series microscopes. Supplied new from stock, part number N4274000.

🔎 Typical Applications

• Fura-2 ratiometric calcium imaging (340/380nm excitation)
• Indo-1 calcium imaging (340nm excitation)
• Ratiometric UV dye imaging requiring high transmission at 340nm
• Multi-channel fluorescence combining UV-excited and visible fluorophores
• DAPI and Hoechst nuclear staining with UV excitation
• Any UV fluorescence application where standard objectives have insufficient 340nm transmission

📊 Key Specifications

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