Title: Affymetrix CHP Analysis (ExpressionStat). Description:
Title: Fluidics Station Protocol. Description:
Title: Affymetrix CEL Analysis (Percentile). Description:
RNA samples were quality controlled using the Agilent 2100 Bioanalyzer. 100 pmol T7-(dT)24 primer (5'-GGCCAGTGAATTGTAATACGACTCACTATAGGGAGGCGG-(dT)24-3') was hybridized with the Total RNA ( 8 - 12ug) at 70°C for 10 minutes. First strand cDNA was synthesized by reverse transcription using 400 units SuperScript II Reverse Transcriptase in a reaction containing 50 mM Tris-HCl (pH 8.3), 75 mM KCl, 3 mM MgCl2, 10 mM dithiothreitol (DTT) and 0.5 mM dNTPs at 42C for 1 hour. The reaction was then put on ice for 2 mins, followed by second strand cDNA synthesis. 130ul of the second strand reaction mix was added to the 20ul first strand synthesis reaction. The second strand reaction mix contained 40 units E. coli DNA polymerase I, 10 units E. coli DNA ligase, 2 units E. coli RNase H and 0.2 mM dNTPs in a buffer containing 20 mMTris-HCl (pH 6.9), 90 mM KCl, 4.6 mM MgCl2, 10mM (NH4)SO4 and 0.15 mM ß-NAD+. The reaction was incubated at 16 C for 2 hours. 10 units T4 DNA Polymerase was added and the reaction incubated for a further 5 minutes at 16 C, then the reaction was terminated using EDTA. The double-stranded cDNA was cleaned up using the cDNA Cleanup Spin Column supplied in the Affymetrix GeneChip Sample Cleanup Module. The double-stranded cDNA was used as a template for in Vitro transcription of biotin-labeled cRNA using the ENZO BioArray RNA Transcript Labeling Kit supplied by Affymetrix. The Transcript Labeling kit produces large amounts of hybridizable biotin-labeled RNA targets by in Vitro transcription from bacteriophage T7 RNA polymerase promoters. The reaction mixture containing Biotin-Labeled ribonucleotides (ATP, GTP, CTP, UTP with Bio-UTP and Bio-CTP), DTT, RNase inhibitor mix and T7 RNA polymerase was incubated at 37 C for 5 hrs, gently mixing every 30 minutes during the incubation. This produced an average of 40ug biotin-labeled cRNA . The biotin-labeled cRNA was cleaned up using the cRNA Cleanup Spin Column supplied in the Affymetrix GeneChip Sample Cleanup Module. The quantity and quality of the cRNA was measured using the Agilent 2100 Bioanalyzer. The total amount of cRNA was calculated, the starting quantity of RNA subtracted to give the quantity of adjusted cRNA. The cRNA was fragmented by metal-induced hydrolysis to break down full-length cRNA to 35-200 base fragments. 15ug of adjusted cRNA was used to prepare 300ul of hybridization cocktail of which 200ul was hybridized with the GeneChip.
Protocol: Qiagen RNAeasy kit protocol
At 21 days germination (Growth Stage 3.4/3.5) Arabidopsis plants were challenged with rigorously sterilised,infective nematodes of H. schachtii as before (Urwin et al., (1997) Plant Journal 12: 455-461). 35 sterile J2s were pipetted onto small ~0.5 mm2 squares of sterile GF/A filter paper. The GF/A paper was left in direct contact with the zone of elongation on 3 lateral roots per plant for 48 hours. Sections of root containing syncytia have been excised from the thin and transparent roots of Arabidopsis and collected into RNAlater solution (Ambion) at 21 days post infection (Growth Stage 6.1). The female nematode has been removed.