IN SITU HYBRIDIZATION IN PRENATAL DIAGNOSIS

该项目的目标是开发显著改进的自动化 检测最常见的细胞遗传学的技术 羊膜穿刺术或绒毛膜活检获得的间期细胞异常 绒毛取样(CVS)。在间期细胞上使用DNA探针可以避免 常规细胞遗传学分析所需的培养。这可以减少 产前诊断的时间和成本，并允许将测试扩展到 高危人群中的一大部分。这样的自动化将是 尤其是当胎儿细胞可以从母体中分离出来时 血样。这将消除与以下方面相关的风险 羊膜穿刺术或CVS并将胎儿非整倍体筛查扩大到 所有怀孕的人。 我们将荧光DNA探针标记和自动图像分析 计数间期细胞的13、18、21、X和Y染色体。我们将使用 (1)独一无二的新型自动显微镜和(2)带有 新近开发的(3)校正数字化彩色图像的算法 用于光谱重叠，以及(4)创建点计数的无偏估计 比例，以及(5)厚样品成像的新方法 用于定位单元格边界。提到的五条染色体说明 在羊膜穿刺术中观察到的绝大多数存活的非整倍体 或者是CVS。快速的非整倍体筛查和性别决定也将有助于 新生儿多发性先天性畸形或多发性畸形的诊断 生殖器。间期细胞的原位杂交分析可以 提供不到24小时的诊断，而不是48-72小时 对外周血进行常规细胞遗传学检查，10-14天后 羊膜穿刺术或CVS。 建议的商业应用：一旦技术开发完成 并符合常规应用条件的，它们将被合并到 PSII的细胞遗传学自动化设备的Powergene产品线，两者 在新系统中，并作为对已在 细胞遗传学实验室。

The goal of this project is to develop significantly improved automated techniques for detecting the most commonly occurring cytogenetic abnormalities in interphase cells obtained by amniocentesis or chorionic villus sampling (CVS). Using DNA probes on interphase cells avoids the culturing required from routine cytogenetic analysis. This can reduce the time and cost of prenatal diagnosis and permit extension of the test to a larger segment of the at-risk population. Such automation will be particularly important when fetal cells can be isolated from maternal blood samples. This would eliminate the risk associated with amniocentesis or CVS and extend fetal aneuploidy screening to virtually all pregnancies. We will fluorescent DNA probe labeling and automated image analysis to count chromosomes 13, 18, 21, X, and Y in interphase cells. We will use (1) a unique new automated microscope and (2) 4-chip CCD camera with recently developed algorithms for (3) correcting digitized color images for spectral overlap, and (4) creating unbiased estimates of dot count proportions, along with (5) new methods for thick specimen imaging and for locating the cell boundary. The five chromosomes mentioned account for the great majority of viable aneuploidies observed at amniocentesis or CVS. Rapid aneuploidy screening and sex determination will also assist diagnosis of newborns with multiple congenital anomalies or ambiguous genitalia. Interphase cell analysis by in situ hybridization could provide a diagnosis is under 24 hours, compared to 48-72 hours for conventional cytogenetics done on peripheral blood and 10-14 days for amniocentesis or CVS. PROPOSED COMMERCIAL APPLICATION: As soon as the techniques are developed and qualified for routine application, they will be incorporated into PSII's PowerGene product line of cytogenetics automation equipment, both in new systems and as an upgrade to existing systems already in use in cytogenetics labs.