METHOD FOR DETECTING AND QUANTIFYING A TARGET MOLECULE IN A SAMPLE

• US 20120258485A1
• Filed: 03/21/2012
• Published: 10/11/2012
• Est. Priority Date: 03/21/2011
• Status: Active Grant

• Current Assignee: ImaBiotech
• Original Assignee: ImaBiotech
• Inventors: STAUBER, JONATHAN, Pamelard, Fabien, Bonnel, David, Hamm, Grégory
• Granted Patent: US 9,182,409 B2
• Time in Patent Office: Days
• US Class Current: 435/23
• CPC Class Codes: G01N 33/4833 of solid biological material, e.g. tissue samples, cell cultures tissue in vivo A61B5/00; cell suspensions G01N33/48735
• CPC Class Codes: G01N 33/6851 Methods of protein analysis involving laser desorption ionisation mass spectrometry
• CPC Class Codes: H01J 49/0004 Imaging particle spectrometry
• CPC Class Codes: H01J 49/0027 Methods for using particle spectrometers
• CPC Class Codes: H01J 49/164 Laser desorption/ionisation, e.g. matrix-assisted laser desorption/ionisation [MALDI] sample holders H01J49/0418

Abstract

The invention relates to a method for identifying and quantifying by mass spectrometry at least one target molecule in a sample, comprising the following steps:

• • a) depositing the sample to be analyzed on a support;
  • b) analyzing the sample by mass spectrometry, so as to obtain the mass spectrum of the target molecule in said sample;
  • c) weighting a signal associated with the mass spectrum of the target molecule in said sample by a extinction coefficient (TEC) specific to the target molecule and to the sample; and
  • d) using the weighted signal of the target molecule to determine the quantity of target molecule in the sample.

Claims

1. A method for detecting and quantifying by mass spectrometry at least one target molecule in a sample, comprising the following steps:

a) depositing the sample to be analyzed on a support;

b) analyzing the sample by mass spectrometry, so as to obtain the mass spectrum of the target molecule in said sample;

c) weighting a signal associated with the mass spectrum of the target molecule in said sample by a extinction coefficient (TEC) specific to the target molecule and to the sample; and

d) using the weighted signal of the target molecule to determine the quantity of target molecule in the sample.

2. The method for detecting and quantifying by mass spectrometry at least one target molecule in a sample according to claim 1, wherein the extinction coefficient (TEC) of the target molecule in the sample to be analyzed corresponds to the ratio of the signal of the target molecule in a reference medium to the signal of the target molecule in the sample, or the inverse.

3. The method for detecting and quantifying by mass spectrometry at least one target molecule in a sample according to claim 1, wherein the TEC is calculated only once for a given target molecule in a given type of sample to be analyzed, and is reused for each quantification of said target molecule in the given type of sample.

4. The method for detecting and quantifying by mass spectrometry at least one target molecule in a sample according to claim 1, wherein the target molecule is a protein, a peptide, a lipid, a metabolite, a small molecule or any molecule that can be ionized by mass spectrometry.

5. The method for detecting and quantifying by mass spectrometry at least one target molecule in a sample according to claim 1, wherein the sample analyzed is an organic or inorganic sample.

6. The method for detecting and quantifying by mass spectrometry at least one target molecule in a sample according to claim 1, wherein the target molecule is a protein and an enzymatic and/or chemical pretreatment of said target molecule is performed prior to detection step b), and wherein detection and quantification are carried out for at least one of the peptides resulting from said pretreatment.

7. The method for detecting and quantifying by mass spectrometry at least one target molecule in a sample according to claim 1, wherein the sample is treated with at least one solvent and/or at least one detergent prior to analysis step b), so as to optimize detection of the target molecule.

8. The method for detecting and quantifying by mass spectrometry at least one target molecule in a sample according to claim 1, wherein the signal associated with the mass spectrum of the target molecule corresponds to the intensity of the peak, the area of the peak or the signal-to-noise ratio of said mass spectrum.

9. The method for detecting and quantifying by mass spectrometry at least one target molecule in a sample according to claim 1, wherein mass spectrometry imaging is used, and wherein the signal intensity of the target molecule is weighted directly on the analyzed sample so as to simultaneously visualize the distribution and the concentration of the target molecule in said sample.

10. The method for detecting and quantifying by mass spectrometry at least one target molecule in a sample according to claim 1, wherein a known concentration of target molecule labeled with deuterium atoms is added to the sample as an internal standard.

11. The method for detecting and quantifying by mass spectrometry at least one target molecule in a sample according to claim 9, wherein a known concentration of target molecule labeled with deuterium atoms is mixed with the matrix before spreading the resulting mixture over the sample.

12. The method for detecting and quantifying by mass spectrometry at least one target molecule in a sample according to claim 10, wherein a known concentration of target molecule labeled with deuterium atoms is mixed with the matrix before spreading the resulting mixture over the sample.

13. The method for detecting and quantifying by mass spectrometry at least one target molecule in a sample according to claim 1, wherein mass spectrometry imaging is used and wherein before analysis step b) the homogeneity of the matrix deposition on the sample is evaluated in relation to a deposition of a reference matrix.

14. The method for detecting and quantifying by mass spectrometry imaging at least one target molecule in a sample according to claim 1, wherein at least two different target molecules in said sample are detected and quantified simultaneously.

15. The method for detecting and quantifying by mass spectrometry at least one target molecule in a sample according to claim 1, wherein the sample is a section of at least one tissue and wherein the target molecule is detected and quantified by mass spectrometry imaging directly on the tissue.

16. The method for detecting and quantifying by mass spectrometry imaging at least one target molecule in a sample according to claim 1, wherein the sample is a section of whole animal and wherein the target molecule is detected and quantified by mass spectrometry imaging directly on said section so as to simultaneously compare the distribution of said target in various tissues of the animal.

17. A computer-readable data medium comprising computer-executable instructions suited to enable a computer system to execute step c) of the method according to claim 1.

18. The computer-readable data medium according to claim 17, comprising a TEC database for at least one target molecule in at least two different sample types.

19. The computer-readable data medium according to claim 17, comprising a database of the reference signal of at least one matrix used in mass spectrometry imaging.

20. The computer-readable data medium according to claim 18, comprising a database of the reference signal of at least one matrix used in mass spectrometry imaging.