Transcription profiling of E12.5 mouse whole embryo and E12.5 placenta total RNA pooled to create 25:75, 50:50, and 75:25 ratio mixtures to estimate transcript copy number

E12.5 mouse whole embryo and E12.5 placenta total RNA were pooled to create 25:75, 50:50, and 75:25 ratio mixtures, based on Bioanalyzer quantitation. These samples, along with the original unmixed RNAs, were used as templates for duplicate linear amplification labeling reactions. cRNA target mixtures were hybridized against a Universal Mouse Reference (Stratagene). Pairwise comparison using the NIA Microarray Analysis (ANOVA) software produced log ratios, which were compared to the expected log ratios for genes showing statistically significant (FDR<0.05) differential expression between unmixed embryo and placenta.以生物分析仪（Bioanalyzer）的定量结果为基准，将E12.5（Embryonic Day 12.5）小鼠全胚胎总RNA与胎盘总RNA混合，制备得到25:75、50:50及75:25三种比例的混合样本。上述混合样本连同未混合的原始RNA样本，均作为模板开展重复线性扩增标记反应。将所得cRNA靶标混合物与通用小鼠参照（Universal Mouse Reference，Stratagene）进行杂交。采用NIA基因芯片分析（ANOVA，方差分析）软件进行两两比较，得到对数比值；随后将该对数比值与未混合胚胎与胎盘间存在统计学显著（错误发现率False Discovery Rate，简称FDR<0.05）差异表达的基因的预期对数比值进行比对。