U2OS array-CGH

Osteosarcoma (OS) is a very aggressive bone tumor characterized by highly abnormal complex karyotypes.This a-CGH is a part of an expriment whose aim was to identify, genomic imbalance, DNA methylation and gene expression profiles of osteosarcoma cell lines. Keywords: comparative genomic hybridization The Agilent Human Genome CGH microarray 44k and 244A (Agilent Technologies, Inc., Palo Alto, USA) were used for U2OS array-CGH experiments. Three μg of Human Genomic DNA from multiple anonymous male donors (Promega Corporation, Madison, USA) and 3 μg of test genomic DNA sample were digested with AluI (5 units) and RsaI (5 units) (Promega) for a minimum of 2 hours at 37C. Digestion quality was assessed by the DNA 1000 LabChip Kit (Agilent 2100 Bioanalyzer, Agilent Technologies). Labelling reactions were performed using the Agilent Genomic DNA Labeling Kit PLUS (Agilent Technologies, Inc., Palo Alto, USA) according to the manufacturer’s directions. Briefly, the reference and sample DNA were labelled with 1.5 - 3 mM Cy5-dUTP or Cy3-dUTP (Agilent Technologies, Inc., Palo Alto, USA), and purified using a Centricon YM-30 filter (Millipore, Billerica, USA). Probe mixture of Cy3-labelled sample DNA, Cy5-labelled reference DNA, 50 μl of 1.0mg/ ml of human Cot-1 DNA (Invitrogen, USA), 52 μl of Agilent 10X Blocking Agent and 260 μl of Agilent 2X Hybridization Buffer (Agilent Technologies, Inc.) was denatured at 100C for 1 minute 30 seconds and incubated at 37C for 30 minutes. The probe was applied to the array using an Agilent microarray hybridization chamber, and hybridized for 40 hours at 65C in a rotating oven (Robbins Scientific, Sunnyvale, USA) at 20 rpm. Arrays were washed according to the manufacturer’s recommendations; air dried, and scanned using an Agilent 2565AA DNA microarray scanner (Agilent Technologies, Inc), and processed using Agilent’s Feature Extraction software. Dye-swapped duplicate experiments were carried out.