|Application:||Gene expression microarray analysis|
|Number of samples:||14|
|Release date:||Apr 25 2006|
|Last update date:||Nov 13 2015|
|Dataset link||Microarray Analysis of Differentially Expressed Genes in Placental Tissue of Severe Preeclampsia|
Placental biopsies were obtained during Caesarean section from both normotensive patients and from those with pre-eclampsia (n = 14) (early onset type; earlier than 31 weeks gestation, n = 6 and late onset type; 31 weeks gestation or later, n = 8). Pre-eclampsia was defined as a blood pressure of higher than 160/110 mmHg, with proteinuria of more than 2g in a 24 hour collection. The expression profiles of approximately 47,669 genes were analyzed using a Whole Human Genome Oligo Microarray Kit (Agilent Technologies). A total of 10 placentas from women with pre-eclampsia and four from normal subjects were used in the hybridizations. Reverse transcription labeling and hybridization was performed using the protocol recommended by the manufacturer. The microarray experiments were then carried out using competitive hybridization experiments with Cy3 and Cy5-labeled targets; one with test placental RNAs from patients or normal control subjects, and another using pooled normal placental RNA as a template control for normalization. The glass slides were scanned using an Agilent G2565BA microarray scanner. Scanned images were then analyzed using Feature Extraction software. The average signal intensities were corrected for median background intensity and transferred with GenBank descriptors to a Microsoft Excel data spreadsheet (Microsoft, Redmond, WA). Data analysis was performed using Genespring software version 6.1 (Silicon Genetics, Redwood City, CA). After intensity dependent normalization (Lowess), the expression levels relative to the control were calculated as a ratio, and the expression profiles were then compared between each pre-eclamptic or normal sample.