qHOS Software for Orthogonal Similarity Determination of Protein Structure

Orthogonal Assessment of Antibody Secondary Structure

The JASCO qHOS spectral comparison program is capable of evaluating secondary structure similarity of proteins via CD and FTIR.

Quick and quantitative orthogonal assessment of protein secondary structure with FTIR and CD.

Similarity Assessment for Secondary Structure of Biosimilars


The far-UV/CD and FTIR spectra of the biosimilar RIABNITM are in excellent agreement with those of the innovator MabThera®, and the distributions of the distances between MabThera® and RIABNITM are close to each other. The p-value is larger than the significance level of 0.05.

Orthogonal Assessment of Antibody Tertiary Structure

With JASCO qHOS, Raman and CD spectroscopy comes together to quantitatively determine spectral similarity for monoclonal antibodies.

Evaluation of Tertiary structure is quickly performed using the qHOS statistical package using a known reference and sample data.

Similarity Assessment for Tertiary Structure of Biosimilars


Similar to the secondary structure, the tertiary structure of MabThera® and RIABNITM show excellent agreement in the near-UV/CD and Raman spectra (Figs. 3a and 3b), and the distribution of the distances between MabThera® and RIABNITM are close to each other (Figs. 3c and 3d). The p-value is larger than the significance level of 0.05.

qHOS provides similarity evaluation with flexibility of methods. Our selected weighting methods avoid issues with spectral intensity weighting often misused with CD.

Three Different Statistical TestsTwo Weighting Methods
Student t-testFor analyzing difference a single sample spectrumNoiseGives more weight to spectral regions with less noise via light level
Welch's t-testFor analyzing differences for multiple samplesSpectra ChangeWeights region where the spectrum is known to change using a given native and denatured spectrum
Two one sided t-test (TOST)Establishes sample equivalence through two t-tests


Click below to view our PEGS 2023 poster on secondary structure.