Systems and methods for automated analysis of cells and tissues
Systems and methods for rapidly analyzing cell containing samples, for example to identify morphology or to localize and quantitate biomarkers are disclosed.
1. A computer implemented method for localizing and quantitating a particular biomarker present in individual cells of interest contained in a tissue sample, comprising:
a) incubating the tissue sample with a stain that specifically labels the biomarker;
b) obtaining, using an optical imaging device, a first in-focus image and a second out-of-focus image, each of the first in-focus image and the second out-of-focus image comprising respective pixel locations having an intensity value for each pixel in the tissue sample;
c) subtracting the second out-of-focus image from the first in-focus image to obtain a third image, wherein for each pixel location a percentage of the out-of-focus image pixel intensity is subtracted from the corresponding in-focus image pixel intensity to obtain the third image; and
d) analyzing the third image to obtain a stain intensity and location of the stain so as to thereby localize and quantitate the biomarker.
2. The method of claim 1 , wherein the stain comprises a fluorophore.
3. The method of claim 1 , wherein the biomarker is selected from the group consisting of a protein, a peptide, a nucleic acid, a lipid or a carbohydrate.
4. The method of claim 1 , wherein the quantitation of the biomarker comprises summing the intensity values of the stain at the pixel locations in the third image and dividing the sum by the number of pixels having intensity values of the stain.
5. The method of claim 1 , wherein the out of focus image is acquired by placing the focal plane below the tissue.
6. The method of claim 5 , wherein the focal plane is placed about eight microns below a top surface of the tissue.
7. The method of claim 1 , wherein the out-of-focus image pixel intensity is subtracted from the in-focus image pixel intensity by a method using a quartile distribution in which the images having a low quartile distribution are subtracted less than the images having a high quartile distribution.
8. The method of claim 1 , wherein the out-of-focus image pixel intensity is subtracted from the in-focus image pixel intensity by a method in which pixel intensity is subtracted less in images having a low signal to noise ratio than in images having a high signal to noise ratio.
9. The method of claim 1 , wherein the tissue is fixed.
10. The method of claim 9 , wherein the tissue is paraffin embedded.
11. The method of claim 1 , wherein the tissue section has a thickness of about five microns.
12. The method of claim 1 , wherein the tissue is a sample in a tissue microarray.
13. The method of claim 1 , wherein the tissue is a whole tissue section.
14. A method for identifying a location for each of a plurality of histospots in an image of a stained cell-containing sample, comprising:
obtaining an image using an optical imaging device; and
using a programmable computer to perform the steps of:
a) removing from the image any of the histospots that are debris and/or are fused histospots;
b) applying a virtual mask that has a size and shape characteristic of a histospot which does not constitute a fused histospot and/or debris within the plurality of spots so as to cover an area of the image having a pixel intensity area which is higher than the pixel intensity area anywhere else in the image;
c) identifying the area as a histospot amongst the plurality of histospots, and temporarily setting the intensity of the image in the area under the mask to zero;
d) repeating steps (b) and (c) until no area is identified having a sufficient intensity to qualify as a histospot;
e) identifying a reference point within each of the histospots; and
f) connecting the reference point within each of the spots to either a nearest neighboring histospot or to an edge of the image;
thereby identifying, based on each of the reference points, the location for each of the plurality of histospots in the image.
15. The method of claim 14 , wherein the cell-containing sample is fixed.
16. The method of claim 14 , wherein the cell-containing sample is paraffin embedded.
17. The method of claim 14 , wherein the cell-containing sample comprises a fluorophore.
18. The method of claim 14 , wherein the imaging device is a microscope.
19. The method of claim 18 , in which the microscope is an upright or inverted optical microscope.
20. The method of claim 18 , in which the microscope is a fluorescent microscope.