ABSTRACT
OBJECTIVE: To describe the basic components of a flow cytometer and the features unique to research and clinical instruments. DATA SOURCES: Recent review articles and textbooks on cytometry or laboratory diagnosis. STUDY SELECTION: Not applicable. DATA EXTRACTION: Performed by the authors. DATA SYNTHESIS: A cytometer is used for counting and measuring the physical and chemical characteristics of cells and other biological particles. A flow cytometer is different from other cytometers in that a single-cell suspension is passed through it in a fluid stream. A flow cytometer is a complex combination of optics, fluidics, and electronics. A labeled cell is forced through the system, causing the cell to scatter light and emit fluorescence. This output is sensed by photodetectors and then amplified and converted to digital signals for storage in computers. This stored data can be displayed or used for further analysis. CONCLUSION: Some instruments can separate cells that meet certain preselected criteria. Therefore, the flow cytometer is widely used in research as well as in clinical immunology and hematology to perform rapid immunophenotyping, cell sorting, and DNA analysis.
Subject(s)
Cell Separation/instrumentation , Flow Cytometry/instrumentation , Cell Separation/methods , DNA/analysis , Equipment Design , Flow Cytometry/methods , Humans , Laboratories , LasersABSTRACT
A condition clinically identical to human conjunctival primary acquired melanosis (PAM) was induced in 16 of 20 Dutch (pigmented) rabbits after weekly topical 60-microliters applications of a 1% solution of 7,12-dimethylbenz[a]anthracene (DMBA) in acetone. Pigment stippling appeared in the conjunctiva as early as 5 weeks after the initial carcinogen application. Confluent patches of flat pigmentation appeared over the palpebral conjunctiva 18 weeks after the onset of treatment and showed progressive lateral enlargement and darkening. Histologically, a spectrum of changes from increased melanin production and melanocytic hyperplasia without atypia (resembling the human condition of PAM without atypia) through atypical melanocytic hyperplasia (resembling human PAM with atypia) was identified. The development of this model permits further investigations to explore and explain the clinically observed phenomenon of waxing and waning of PAM and its promotion to conjunctival malignant melanoma.
