MARKER QUANTITATION IN SINGLE CELLS IN TISSUE SECTIONS
Improved assays incorporating single-cell based image analyses that enable quantitation of expression of individual cellular proteins and heterogeneity in terms of individual cellular protein molecule numbers per cell at the single cell level and mapped across sections of clinical tissue samples are disclosed.
1 . A method of quantitatively measuring levels of a cellular protein in each of a plurality of cells in a section of a tissue sample so as to obtain an at least two dimensional (e.g., length and width) map of quantified density distribution of the cellular protein across the section, the method comprising:
preparing a section from a tissue sample, said section comprising identifiable cells;
staining the section with a first stain specific to the cellular protein, a second stain specific to cell nuclei, and a third stain allowing the discrimination of target cells from non-target cells, wherein the first, second and third stains are distinguishable from each other when the stained section is imaged;
obtaining one or more microscopic images of the section wherein the first, second and third stains can be discriminated
identifying target cells within the one or more images based upon staining with the second and third stains;
measuring the intensity of staining with the first stain for a plurality of the identified target cells to obtain a plurality of cellular protein staining intensity data for individual cells and recording cell location coordinate data in association with cellular protein staining intensity data for each individual cell;
ascertaining a level of stained cellular protein that is detected in each identified target cell by comparing stain intensity of the cellular protein in each identified target cell with stain intensity of the cellular protein in each of a plurality of standard cell preparations, the plurality including multiple standard cell preparations having differing known levels of expression of the cellular protein;
creating a map of quantity distribution of the cellular protein in each of the target cells within a region of the section.
2 . The method of claim 1 , wherein
a) the tissue sample is a tumor sample,
b) the target cells are malignant cells, and
c) the non-target cells are stromal cells.
3 . The method of claim 1 , wherein the cellular protein is a cell surface receptor.
4 . The method of claim 3 , wherein the cell surface receptor is a growth factor receptor.
5 . The method of claim 4 , wherein the growth factor receptor is an EGFR family receptor.
6 . The method of claim 5 , wherein the EGFR family receptor is HER2, HER3, or EGFR.
7 . The method of claim 1 , wherein the quantity distribution of the cellular protein is a continuous distribution.
8 . The method of claim 1 , wherein the first stain comprises an antibody specific to the cellular protein.
9 . The method of claim 1 , wherein the second stain is a DNA stain.
10 . The method of claim 9 , wherein the second stain comprises either or both of DAPI and a Hoechst® stain.
11 . The method of claim 1 , wherein the third stain comprises an antibody.
12 . The method of claim 11 , wherein the antibody comprised by the third stain is specific to a cytokeratin.
13 . The method of claim 1 , wherein the map is in the form of a complementary cumulative distribution.
14 . The method of claim 1 , wherein the identifying and measuring and ascertaining are done by automated image analysis.
15 . The method of claim 1 , wherein the plurality of the identified target cells comprises at least 500 cells.
16 . The method of claim 1 , wherein the plurality of the identified target cells comprises at least 1,000 cells.
17 . The method of claim 1 , wherein the plurality of the identified target cells comprises at least 2,000 cells.
18 . The method of claim 1 , wherein the plurality of standard cell preparations is in the form of an array of stained standard cells.
19 . The method of claim 8 , wherein the antibody is a labeled antibody.
20 . The method of claim 8 , wherein the antibody is an unlabeled antibody that is subsequently labeled with a labeled secondary antibody specific to an antibody type characteristic of the first antibody.