A method for identifying candidate target cells within a biological fluid specimen, comprising: providing a biological fluid specimen previously collected; preparing the biological fluid specimen by staining cell nuclei in the biological fluid specimen with a first bio-conjugated dye having a first color and configured to bind nucleic acids in the cell nuclei of the target cells, and staining cytoskeletal cell features in the biological fluid specimen with a second bio-conjugated dye having a second color and configured to bind to cytoskeletal cell features of the target cells; capturing a digital image of the biological fluid specimen, the digital image having a plurality of color channels; and applying image analysis to the digital image including receiving the digital image in a computer, identifying, in the computer, first connected regions of pixels of a minimum first intensity in a first channel of the plurality of color channels, identifying, in the computer, second connected regions of pixels of a minimum second intensity in a second channel of the plurality of color channels, determining, in the computer, first connected regions and second connected regions that spatially overlap, determining, in the computer, an aspect ratio of the spatially overlapping first connected regions and second connected regions based on a color channel of the plurality of color channels, identifying, in the computer, first connected regions and second connected regions that spatially overlap and for which the aspect ratio meets an aspect ratio threshold; providing a portion of the image corresponding to a remaining identified spatially overlapping first connected region and second connected region to a classifier as candidates for classification. providing a biological fluid specimen previously collected; preparing the biological fluid specimen by staining cell nuclei in the biological fluid specimen with a first bio-conjugated dye having a first color and configured to bind nucleic acids in the cell nuclei of the target cells, and staining cytoskeletal cell features in the biological fluid specimen with a second bio-conjugated dye having a second color and configured to bind to cytoskeletal cell features of the target cells; capturing a digital image of the biological fluid specimen, the digital image having a plurality of color channels; and applying image analysis to the digital image including receiving the digital image in a computer, identifying, in the computer, first connected regions of pixels of a minimum first intensity in a first channel of the plurality of color channels, identifying, in the computer, second connected regions of pixels of a minimum second intensity in a second channel of the plurality of color channels, determining, in the computer, first connected regions and second connected regions that spatially overlap, determining, in the computer, an aspect ratio of the spatially overlapping first connected regions and second connected regions based on a color channel of the plurality of color channels, identifying, in the computer, first connected regions and second connected regions that spatially overlap and for which the aspect ratio meets an aspect ratio threshold; providing a portion of the image corresponding to a remaining identified spatially overlapping first connected region and second connected region to a classifier as candidates for classification. receiving the digital image in a computer, identifying, in the computer, first connected regions of pixels of a minimum first intensity in a first channel of the plurality of color channels, identifying, in the computer, second connected regions of pixels of a minimum second intensity in a second channel of the plurality of color channels, determining, in the computer, first connected regions and second connected regions that spatially overlap, determining, in the computer, an aspect ratio of the spatially overlapping first connected regions and second connected regions based on a color channel of the plurality of color channels, identifying, in the computer, first connected regions and second connected regions that spatially overlap and for which the aspect ratio meets an aspect ratio threshold; providing a portion of the image corresponding to a remaining identified spatially overlapping first connected region and second connected region to a classifier as candidates for classification.