Systems and methods for sample analysis using swabs
The invention generally relates to systems and methods for sample analysis using swabs. In certain aspects, the invention provides systems that include a probe having a conductive proximal portion coupled to a porous material at a distal portion of the probe that is configured to retain a portion of a sample that has contacted the porous material, and a mass spectrometer having an inlet. The system is configured such that the porous material at a distal portion of the probe is aligned over the inlet of the mass spectrometer.
1. A method for assessing a tissue for presence of one or more cancer cells, the method comprising:
contacting a medical swab to a tissue in a manner that a portion of the tissue is retained on the medical swab;
generating ions of one or more analytes from the portion of the tissue retained on the medical swab by:
positioning the portion of the tissue directly vertically above a distal end of an upward opening inlet of a mass spectrometer; and
applying solvent and voltage to the portion of the tissue to generate ions thereof that are downwardly expelled from the swab and into the upward opening inlet; and
analyzing the ions in the mass spectrometer to detect one or more analytes from the tissue that is indicative of presence of one or more cancer cells in the tissue, thereby assessing the tissue for the presence of the one or more cancer cells in the tissue.
2. The method according to claim 1 , wherein the in vivo tissue is tissue at a resection site in a patient.
3. The method according to claim 2 , wherein the analyzing allows for assessment of tumor infiltration into the resection site.
4. The method of claim 1 , wherein the one or more analytes are lipids.
5. The method of claim 1 , wherein the one or more analytes are N-acetylaspartate (NAA).
6. The method of claim 5 , wherein decreased abundance of NAA is indicative of an increase in tumor cell percentage within the tissue as compared to noncancerous tissue.
7. The method of claim 1 , wherein one or more analytes is 2HG.
8. The method of claim 7 , wherein 2HG is associated with a mutant form of glioma.
9. The method of claim 8 , wherein an increase in average 2HG levels in cancerous tissue is indicative of an IDH-mutant glioma as compared to a wild-type glioma.
10. The method of claim 1 , wherein the method is performed in the context of an intraoperative approach.