|
Comparative Mass Spectrometry
The analysis of mass spectra of biological samples (tissue, serum, etc) is a promising
avenue towards the discovery of clinically relevant bio-markers. As a starting point, this type of analysis requires
a convincing demonstration of the statistical significance of the observed spectral differences between biological samples.
Once the significance of observed features is confirmed, the researcher can proceed with further investigation of the
molecular nature of the peaks of interest (e.g. aiming at creating the immuno-histochemical assays with satisfactory
sensitivity and specificity), or use these features directly for mass-spectrometry based diagnostic tests.
The reliable and reproducible detection of statistically significant
differences between mass spectra is a complex problem that involves facing a variety of difficult
technical challenges, such as:
Dealing with background that can change from spectrum to spectrum,
and also within a single spectrum: Any solution requires a reliable background subtraction method.
Detecting peaks and other features in the spectra in the presence of noise that can also change
substantially, both within a spectrum and from spectrum to spectrum: Any solution requires a method
for local estimation of the noise strength.
Dealing with spectra misaligned in m/z, due to the (almost always present) slight
mis-calibration: Any solution requires a reliable alignment method.
Dealing with spectra that do not allow unambiguous classification. Performing classification
of the unknown spectrum as belonging to the disease or control group, it is important to be able to
quantitatively characterize the confidence of classification, and to recognize and report the spectra
that cannot be classified with the required confidence.
 |
|
Raw mass spectra from the same patient from Colorado University (CU)
and Vanderbilt University (VU) before pre-processing. |
 |
|
Raw mass spectra from the same patient from Colorado University (CU)
and Vanderbilt University (VU) after pre-processing. |
** All References within these publications to Efeckta Technologies Corporation
should be considered Biodesix Inc. as Biodesix Inc. now maintains sole ownership of all Efeckta Technologies Corporation assets as of 04/2006.
For more details and inquires about our services: call 303.417.0500
|