Syringing as a method of cell dispersal. II. Effect on abnormal cells.

The generation of turbulent shear force using a constant pressure syringing device has been demonstrated to be a simple, effective method for the dispersal of intermediate and superficial squamous cells. This paper reports results of an evaluation of the effects of syringing on the dispersal of abnormal cells. Gynecologic cell samples obtained from preinvasive and invasive lesions were syringed. Overall cell loss, as well as degree of dispersion, was evaluated. Doublet, triplet and larger abnormal cell groupings remained in most syringed aliquots regardless of pressure. Although some cell loss was observed in the majority of cases, the percentage of single abnormal cells was increased in 96% of the syringed aliquots.

A poststaining fixation technique for acridine orange: quantitative aspects.

A poststaining fixation technique was developed for acridine orange staining of cytologic specimens. A quantitative evaluation was performed to assess the suitability of this technique for routine use in analytic cytology and its potential for future use in automated screening equipment. Three major advantages of the poststaining fixation technique over conventional acridine orange staining methods were documented: (1) stained cells may be stored for several months without alteration of cellular morphology or fluorescence characteristics; (2) the protocol minimizes diffusion of stain out of cells; and (3) poststaining fixation reduces dependence of nuclear or total cell fluorescence on cell distribution or concentration on a slide or in flow.

False alarms in a slit-scan flow system: causes and occurrence rates. Implications and potential solutions.

A slit-scan technique was developed as a basis for an automated prescreening system for gynecologic cytology. A flow system based on this technique was fabricated and tested and results indicated that false alarms (misclassification of objects or events from normal specimens as abnormal) are the greatest remaining obstacle to development of an automated prescreening instrument. A dual view correlation system was fabricated to provide exact image-contour correlation in flow and permit precise determination of causes and occurrence rates of false alarms. This paper presents data from correlation analyses of 23 normal cytologic specimens. Major causes of false alarms and their implications to automated prescreening are discussed. A technique that would eliminate the majority of false alarms in flow is presented.

Imaging systems for correlation of false alarms in flow.

False alarms, arising from a variety of sources, are the greatest remaining obstacle to development of an automated prescreening system for gynecologic cytology. This paper describes two correlation systems under development at the University of Rochester and discusses their utilization in the study of false alarms in slit-scan cytofluorometry. Both systems permit imaging of objects in flow and correlation between images and corresponding slit-scan contours. Correlation systems will permit a detailed study of false alarm causes and aid in the search for new features to assist in their recognition.

A new post-staining fixation technique for Acridine Orange.

A technique for Acridine Orange staining of cells for automated flow analysis involving post-staining fixation with Millonig's glutaraldehyde buffer is presented. Preliminary data indicate that with this protocol there is decreased background fluorescence and increased signal to noise ration in flow. In addition, stained cells may be stored for several months without alteration in cellular morphology or fluorescence characteristics. Finally, nuclear and cytoplasmic fluorescence do not appear to vary significantly with respect to cell concentration or distribution on a slide or filter when cells are stained according to the glutaraldehyde protocol.

Slit-scan cytofluorometry. Basis for automated prescreening of urinary tract cytology.

A study was undertaken to assess the applicability of the slit-scan technique to automated prescreening of urinary tract cytology. Cells from voided and catheterized urines were stained with acridine orange and measured on a static cell slit-scan cytofluorometer. Analysis of data from the specimens indicates that nuclear fluorescence alone appears adequate for recognition of abnormal specimens. Remaining problems in the automation of urinary tract cytology prescreening are discussed.