Devices and methods for determining and/or isolating cells such as circulating cancer or fetal cells

Abstract

Some embodiments of the present invention generally relate to devices and methods for determining and/or isolating cells. For example, one aspect is generally directed to methods and devices for detecting, identifying, counting, and/or potentially sorting cells of interest in blood or other biological sample. In some embodiments, blood samples (or other biological fluids) may be treated with signaling entities, such as pH-sensitive entities, that change color or otherwise produce a signal in suitable internal environments. For example, certain cells, such as cancer or fetal cells, may have differences in intracellular pH compared to other cells, which can be detected using pH-sensitive entities. In certain embodiments, the cells may be sorted based on such signaling entities; for example, illumination of cells in a suitable machine for sorting cells (e.g., using fluorescent light) may allow determination of the cells, which may also be recovered or isolated for further manipulation in some cases.

What is claimed is: 
     
         1 . A method of determining target cells of interest within a fluid, the method comprising:
 exposing a fluid containing target cells of interest and non-target cells to a pH-sensitive entity, wherein the pH-sensitive entity has a first state within the target cells of interest and a second state within the non-target cells;   determining the pH-sensitive entity internally within at least some of the cells within the fluid; and   determining the target cells of interest based on the determination of the pH-sensitive entity within the cells.   
     
     
         2 . The method of  claim 1 , wherein the target cells of interest are tumor cells. 
     
     
         3 . The method of  claim 1 , wherein the target cells of interest are fetal cells. 
     
     
         4 . The method of  claim 1 , wherein the target cells of interest have an intracellular pH that is at least about 0.1 pH units higher than an intracellular pH of the non-target cells. 
     
     
         5 . The method of  claim 1 , wherein the fluid is blood. 
     
     
         6 . The method of  claim 1 , wherein the fluid is amniotic fluid. 
     
     
         7 . The method of  claim 1 , wherein the fluid is blood, cervical fluid, vaginal fluid, cerebral spinal fluid, urine, nipple aspirate, sputum, pleural or abdominal exudate or transudate. 
     
     
         8 . The method of  claim 1 , further comprising acidifying the fluid. 
     
     
         9 - 10 . (canceled) 
     
     
         11 . The method of  claim 8 , wherein acidifying the fluid comprises introducing an acid to the fluid. 
     
     
         12 - 13 . (canceled) 
     
     
         14 . The method of  claim 1 , further comprising counting the target cells of interest. 
     
     
         15 . The method of  claim 1 , wherein the pH-sensitive entity comprises one or more of 2′,7′-bis(2-carboxyethyl)-5(6)-carboxyfluorescein tetrakis(acetoxymethyl) ester (BCECF AM), 5(6)-carboxy-2′,7′-dichlorofluorescein, 5(6)-carboxyfluorescein, 5(6)-carboxyfluorescein diacetate, 5(6)-carboxyfluorescein N-hydroxysuccinimide ester, 3,6-diacetoxyphthalonitrile, 6,8-dihydroxy-1,3-pyrenedisulfonic acid disodium salt, Eosin diacetate, or naphthofluorescein. 
     
     
         16 - 17 . (canceled) 
     
     
         18 . The method of  claim 1 , wherein the pH-sensitive entity is fluorescent at a pH of greater than about 7.5 and substantially less fluorescent at a pH of less than about 7. 
     
     
         19 . The method of  claim 1 , further comprising isolating at least some of the target cells of interest. 
     
     
         20 . The method of  claim 19 , further comprising performing genetic analysis of the isolated cells. 
     
     
         21 . The method of  claim 20 , wherein said genetic analysis includes a search for genetic abnormalities. 
     
     
         22 . The method of  claim 19 , comprising sequencing DNA from the isolated cells. 
     
     
         23 . The method of  claim 19 , further comprising performing morphology analysis and/or cytopathology analysis of the isolated cells. 
     
     
         24 . (canceled) 
     
     
         25 . The method of  claim 19 , further comprising determining gene expression of the isolated cells. 
     
     
         26 . The method of  claim 19 , further comprising determining a metabolic profile of the isolated cells. 
     
     
         27 . The method of  claim 19 , comprising isolating at least some of the target cells of interest using a cell cytometer. 
     
     
         28 - 29 . (canceled) 
     
     
         30 . The method of  claim 1 , further comprising determining a clinical condition of a subject based on the determination of the target cells of interest. 
     
     
         31 . The method of  claim 30 , wherein determining the clinical condition comprises determining a stage or type of cancer. 
     
     
         32 - 33 . (canceled) 
     
     
         34 . The method of  claim 1 , wherein the target cells of interest arise from a fetus presently carried by the subject that the fluid arises from. 
     
     
         35 - 36 . (canceled) 
     
     
         37 . The method of  claim 1 , further comprising exposing the cells to an antibody. 
     
     
         38 . The method of  claim 37 , wherein the antibody is able to recognize a tumor-specific antigen. 
     
     
         39 . The method of  claim 38 , wherein the tumor-specific antigen is EpCAM, EphB4, HER2, EGFR, CEA, MUC-1, or CD45. 
     
     
         40 . The method of  claim 37 , wherein the antibody is able to recognize a cell antigen. 
     
     
         41 . The method of  claim 40 , wherein the cell antigen is CD4, CD8, CD45, CD71, or anti-eplison globin. 
     
     
         42 - 181 . (canceled) 
     
     
         182 . The method of  claim 1 , wherein the target cells of interest are stem cells. 
     
     
         183 . The method of  claim 182 , wherein the stem cells are fetal stem cells, cord blood stem cells, embryonic stem cells, adult stem cells, tissue-specific stem cells, or induced pluripotent stem cells. 
     
     
         184 . The method of  claim 1 , wherein the fluid arises from a homogenized tissue sample. 
     
     
         185 . The method of  claim 1  wherein the fluid comprises a cell fraction. 
     
     
         186 . The method of  claim 19 , further comprising determining genotype of the isolated cells. 
     
     
         187 . The method of  claim 19 , further comprising culturing the isolated cells. 
     
     
         188 . The method of  claim 19 , further comprising determining response of the isolated cells to a drug. 
     
     
         189 . The method of  claim 19 , comprising isolating at least some of the target cells of interest using a fluorescent microscope.