RESUMO
This unit presents a brief overview of the principles of quality control in the clinical laboratory.
Assuntos
Laboratórios/normas , Controle de Qualidade , Animais , Química Clínica/normas , Citometria de Fluxo/métodos , Humanos , Luz , Reprodutibilidade dos TestesRESUMO
The purpose of a control is to aid the operator in deciding whether an analytical system is producing reliable results for a given assay, and ultimately whether to release the results. This unit presents information on the techniques for determining when results are in control or out of control.
Assuntos
Química Clínica/normas , Controle de Qualidade , Animais , Química Clínica/métodos , Técnicas de Laboratório Clínico/normas , Reações Falso-Negativas , Reações Falso-Positivas , Humanos , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
This unit proposes a specific daily quality control program to ensure instrument reliability and accurate results within current constraints.
Assuntos
Citometria de Fluxo/normas , Imunofenotipagem/métodos , Corantes Fluorescentes/normas , Humanos , Fenótipo , Controle de Qualidade , Padrões de Referência , Valores de Referência , Reprodutibilidade dos TestesRESUMO
All flow cytometry systems require instrument quality control procedures such as are described for phenotyping. However, there are additional considerations for DNA analysis beyond those outlined for other types of analyses. Because flow cytometric analysis of cellular DNA content is an established procedure for measurement of DNA ploidy of tumors and of the fraction of cells in the S phase of the cell cycle two parameters that have prognostic utility in clinical oncology careful quality control of this type of analysis is essential. This unit discusses the quality control issues peculiar to quantitative analysis of cellular DNA content and provides information complementary to many of the units in this chapter.
Assuntos
Separação Celular/métodos , Citometria de Fluxo/métodos , Ácidos Nucleicos/análise , Controle de Qualidade , Animais , Ciclo Celular , DNA/análise , DNA/química , Humanos , Inflamação , Oncologia/métodos , Necrose , Ácidos Nucleicos/química , PrognósticoRESUMO
Clinical flow cytometry has evolved from two-parameter quantitative assessment of peripheral blood lymphocytes to six-parameter qualitative evaluation of bone marrow for hematopathology. Leukemia and lymphoma immunophenotyping represent an extremely important complement to morphology in the diagnosis and monitoring of hematopoietic malignancies. The complexity of five- and six-parameter analyses and the interpretation of the data rely on standardization and validation of the instrument, the reagents and the procedure. In addition, flow cytometry laboratories in the U.S. are required to document proficiency testing, sample preparation, method accuracy, specificity, sensitivity and precision. NCCLS and the U.S.-Canadian Consensus Conference have provided recommendations, but each laboratory is ultimately responsible for validating its own qualitative and quantitative procedures. This paper reviews procedures for validation and quality control of all aspects of the operation of a clinical flow cytometry service.
Assuntos
Citometria de Fluxo/normas , Imunofenotipagem/normas , Patologia Clínica/normas , Sobrevivência Celular , Interpretação Estatística de Dados , Citometria de Fluxo/métodos , Fluorescência , Humanos , Imunofenotipagem/instrumentação , Imunofenotipagem/métodos , Controle de Qualidade , Reprodutibilidade dos Testes , Coloração e RotulagemRESUMO
An automated device has been developed to prepare a wide variety of cytology preparations. Using the device, cells collected in suspension are mildly dispersed and transferred to a glass slide using filter-transfer technology. The cell density on the slide is controlled by the instrument. A companion product, the solution used in specimen transport and preparation, provides long-term preservation of diagnostic cells while lysing red blood cells. The overall process yields clean, uniform samples with better visualization of the diagnostic cells. The use of a disposable filter prevents sample-to-sample contamination. Collection of the sample in solution makes it possible to produce multiple slides from one sample.
Assuntos
Biologia Celular/instrumentação , Feminino , Humanos , Manejo de Espécimes/instrumentação , Manejo de Espécimes/métodos , Esfregaço Vaginal/métodosRESUMO
Recent clinical trials indicated that the ThinPrep method of sample preparation has greater diagnostic sensitivity than the conventional direct Papanicolaou smear. The authors hypothesized that nonhomogeneous cell sampling during transfer from the sampling device to the microscope slide was a contributing factor to the reduced accuracy of the conventional direct Pap smears in these trials. To test this hypothesis, four direct smear methods were compared with the newly developed, fluid-based, filter-transfer method. Counts of epithelial cells on conventional smears showed that only a fraction of the available epithelial cells on the sampling devices (medians, 6.5% to 62.5%) was actually deposited on the slides. In all 27 cases studied with the ThinPrep method, equivalent diagnostic material was obtained on each of the replicate slides prepared per specimen. This identifies a new source of error, preparation error, in conventional smears.
