Cell-to-cell variation in gene expression creates a need for techniques that can characterize expression at the level of individual cells. This is particularly true for rare circulating tumour cells, in which subtyping and drug resistance are of intense interest. Here we describe a method for cell analysis—single-cell mRNA cytometry—that enables the isolation of rare cells from whole blood as a function of target mRNA sequences. This approach uses two classes of magnetic particles that are labelled to selectively hybridize with different regions of the target mRNA. Hybridization leads to the formation of large magnetic clusters that remain localized within the cells of interest, thereby enabling the cells to be magnetically separated. Targeting specific intracellular mRNAs enablescirculating tumour cells to be distinguished from normal haematopoietic cells. No polymerase chain reaction amplification is required to determine RNA expression levels and genotype at the single-cell level, and minimal cell manipulation is required. To demonstrate this approach we use single-cell mRNA cytometry to detect clinically important sequences in prostate cancer specimens.

基因表达中的细胞间差异引起了对可表征单个细胞水平表达的技术的需求。对于罕见的循环肿瘤细胞尤其如此，其中亚型和耐药性受到了极大的关注。在这里，我们描述了一种用于细胞分析的方法-单细胞mRNA细胞计数法，该方法能够根据目标mRNA序列从全血中分离稀有细胞。这种方法使用两类磁性颗粒，这些磁性颗粒被标记为与靶mRNA的不同区域选择性杂交。杂交导致形成大的磁簇，这些大的磁簇保持定位在感兴趣的细胞内，从而使细胞被磁性分离。靶向特定细胞内mRNA可使循环肿瘤细胞与正常造血细胞区分开。无需聚合酶链反应扩增即可确定单细胞水平的RNA表达水平和基因型，并且只需进行最少的细胞操作即可。为了证明这种方法，我们使用单细胞mRNA细胞计数法检测前列腺癌标本中的临床重要序列。