Raman Spectroscopy

Find out what organic and proteinaceous particles are in your sample

Get a perfect match for your particles

One of the most common reasons for the recall of biopharmaceutical products is the presence of unidentified particulates. Particulates can show up from packaging, processing equipment, contaminants in the process, or the drug product itself. Identifying the particle is the first and most critical step in tracing it back to the source.

Raman spectroscopy is a great technology for identifying the chemical composition of unwanted organic and proteinaceous particles contaminating your product. It measures the vibrational energy of molecules and, because the vibrational energy profile is unique to every molecular structure, Raman spectroscopy can provide a higher degree of specificity than many other solid particle spectroscopic techniques. With Raman spectroscopy, you can get fast and accurate particle identification for quick and effective elimination of the contaminant at its source.

What’s so great about Raman?

Raman is fast, easy, and works with almost any sample type.

  • Fast—as little as 1 second/measurement
  • Flexible—different wavelengths to ID a wide variety of materials
  • Easy—sample prep is a breeze
  • Robust—no interference from water like FTIR
What’s Raman all about?

Raman spectroscopy uses a laser of a specific wavelength to map out the structural fingerprint of a compound based on the chemical bonds present. Take a deeper dive into how that works:

Hit up those bonds

Photons from the Raman laser are absorbed by the target molecule, causing it to transition to an excited vibrational state. The vibrational state is dependent on the molecule’s chemical composition and structure.

Hit up those bonds_r4
Take it down a notch

After the molecule scatters a photon, the molecule will relax. With Stokes Raman scattering the molecule takes some vibrational energy from the light, so the relaxed state is higher energy than the original state of the molecule. This means the scattered photon has less vibrational energy than it started with.

Take it down a notch_r3
Get a fingerprint

Raman spectroscopy detects the changes in the vibrational energy of the scattered light, providing a chemical fingerprint of the material analyzed.

Asset 3
Find a match

This chemical fingerprint can then be compared to a Raman reference database. Just like an actual fingerprint, you can compare the shape of each individual feature, or peak, to find the perfect match.

ID wipe_aggregates_r2
Wavelength matters

With Raman spectroscopy, the wavelength of the laser you use will affect the type of material you can identify. In general, lower wavelengths of light deliver more energy, which means more scattering but also more fluorescence. Plastics are readily Raman active so they can be analyzed with a higher wavelength laser, but proteins require more energy from a lower wavelength laser to generate enough Raman scattering. When dealing with unknown particles it is difficult to know in advance which wavelength will produce the best Raman signal, so having an instrument with multiple lasers can ensure comprehensive particle identification.

Cellulose acetate


Combining automated microscopy, Raman spectroscopy, and Laser Induced Breakdown Spectroscopy (LIBS) in a single instrument, Hound enables manual and automated identification of visible and subvisible particles across a wide range of chemical compositions. Count, size, and ID particles by their chemical or elemental fingerprints, all with a single easy-to-use instrument.

Ready for more?

Biopharma scientists can now use the right tool for particle analysis and identification challenges with an instrument that combines Raman spectroscopy, laser induced breakdown spectroscopy (LIBS), and light microscopy. Have a question or ready to find out more?