LP520 Longpass Filter (T>90%@525-1200nm, OD6@200-510nm)

Fluorescence Microscopy & Imaging

The most common and "perfect fit" application for this filter is as an Emission Filter for green fluorophores.

• Target Fluorophores: Green Fluorescent Protein (GFP), FITC (Fluorescein isothiocyanate), Alexa Fluor 488, and Cy2.

Recommended Light Sources

• High-Power Blue LEDs (470 nm or 490 nm):

Why recommended: These are the modern standard for widefield microscopy. They are stable, instant-on/off, and emit a narrow spectrum of blue light that sits perfectly within the blocking range of your LP520 filter (OD6 blocking).

• 488 nm Solid-State or Argon Lasers:

Why recommended: Used primarily in confocal microscopy or flow cytometry. They provide coherent, intense light exactly at the excitation peak of GFP.

• Mercury or Metal Halide Arc Lamps (with Excitation Filter):

Why recommended: These are traditional broadband "white light" sources. To use them, you must place a Blue Bandpass Excitation Filter (e.g., 470/40 nm) in front of the lamp to discard all wavelengths except the blue light needed for excitation.

Raman Spectroscopy

Used to block the Rayleigh scattering from blue excitation lasers (e.g., 488 nm) while allowing the Stokes-shifted Raman signal (which appears at longer wavelengths) to pass.

Recommended Light Sources

• 488 nm Blue Laser

For the Raman Spectroscopy setup you described (blocking Rayleigh scattering while passing Stokes-shifted signals), the recommended light source is a 488 nm Blue Laser.

• 488 nm CW Laser

Unlike fluorescence microscopy which can use LEDs, Raman spectroscopy requires a Laser (Light Amplification by Stimulated Emission of Radiation).