The Central Dogma
Life - a recipe for making proteins DNA protein RNA Translation Transcription
ATCTTTTTCGGCTTTTTTTAGTATCCACAGAGGTTATCGACAACATTTTCACA TTACCAACCCCTGTGGACAAGGTTTTTTCAACAGGTTGTCCGCTTTGTGGAT AAGATTGTGACAACCATTGCAAGCTCTCGTTTATTTTGGTATTATATTTGTGT TTTAACTCTTGATTACTAATCCTACCTTTCCTCTTTATCCACAAAGTGTGGAT AAGTTGTGGATTGATTTCACACAGCTTGTGTAGAAGGTTGTCCACAAGTTGT GAAATTTGTCGAAAAGCTATTTATCTACTATATTATATGTTTTCAACATTTAAT GTGTACGAATGGTAAGCGCCATTTGCTCTTTTTTTGTGTTCTATAACAGAGA AAGACGCCATTTTCTAAGAAAAGGAGGGACGTGCCGGAAGATGGAAAATAT ATTAGACCTGTGGAACCAAGCCCTTGCTCAAATCGAAAAAAAGTTGAGCAA ACCGAGTTTTGAGACTTGGATGAAGTCAACCAAAGCCCACTCACTGCAAGG CGATACATTAACAATCACGGCTCCCAATGAATTTGCCAGAGACTGGCTGGAG TCCAGATACTTGCATCTGATTGCAGATACTATATATGAATTAACCGGGGAAGA ATTGAGCATTAAGTTTGTCATTCCTCAAAATCAAGATGTTGAGGACTTTATGC CGAAACCGCAAGTCAAAAAAGCGGTCAAAGAAGATACATCTGATTTTCCTCA AAATATGCTCAATCCAAAATATACTTTTGATACTTTTGTCATCGGATCTGGAA ACCGATTTGCACATGCTGCTTCCCTCGCAGTAGCGGAAGCGCCCGCGAAAG CTTACAACCCTTTATTTATCTATGGGGGCGTCGGCTTAGGGAAAACACACTT AATGCATGCGATCGGCCATTATGTAATAGATCATAATCCTTCTGCCAAAGTGG TTTATCTGTCTTCTGAGAAATTTACAAACGAATTCATCAACTCTATCCGAGAT AATAAAGCCGTCGACTTCCGCAATCGCTATCGAAATGTTGATGTGCTTTTGA TAGATGATATTCAATTTTTAGCGGGGAAAGAACAAACCCAGGAAGAATTTTT CCATACATTTAACACATTACACGAAGAAAGCAAACAAATCGTCATTTCAAGT GACCGGCCGCCAAAGGAAATTCCGACACTTGAAGACAGATTGCGCTCACGT TTTGAATGGGGACTTATTACAGATATCACACCGCCTGATCTAGAAACGAGAA TTGCAATTTTAAGAAAAAAGGCCAAAGCAGAGGGCCTCGATATTCCGAACG AGGTTATGCTTTACATCGCGAATCAAATCGACAGCAATATTCGGGAACTCGA AGGAGCATTAATCAGAGTTGTCGCTTATTCATCTTTAATTAATAAAGATATTA ATGCTGATCTGGCCGCTGAGGCGTTGAAAGATATTATTCCTTCCTCAAAACC GAAAGTCATTACGATAAAAGAAATTCAGAGGGTAGTAGGCCAGCAATTTAAT ATTAAACTCGAGGATTTCAAAGCAAAAAAACGGACAAAGTCAGTAGCTTTTC CGCGTCAAATCGCCATGTACTTATCAAGGGAAATGACTGATTCCTCTCTTCC TAAAATCGGTGAAGAGTTTGGAGGACGTGATCATACGACCGTTATTCATGCG CATGAAAAAATTTCAAAACTGCTGGCAGATGATGAACAGCTTCAGCAGCATG TAAAAGAAATTAAAGAACAGCTTAAATAGCAGGACCGGGGATCAATCGGGG AAAGTGTGAATAACTTTTCGGAAGTCATACACAGTCTGTCCACATGTGGATA GGCTGTGTTTCCTGTCTTTTTCACAACTTATCCACAAATCCACAGGCCCTAC TATTACTTCTACTATTTTTTATAAATATATATATTAATACATTATCCGTTAGGAG GATAAAAATGAAATTCACGATTCAAAAAGATCGTCTTGTTGAAAGTGTCCAA GATGTATTAAAAGCAGTTTCATCCAGAACCACGATTCCCATTCTGACTGGTA TTAAAATTGTTGCATCAGATGATGGAGTATCCTTTACAGGGAGTGACTCAGA TATTTCTATTGAATCCTTCATTCCAAAAGAAGAAGGAGATAAAGAAATCGTC ACTATTGAACAGCCCGGAAGCATCGTTTTACAGGCTCGCTTTTTTAGTGAAA TTGTAAAAAAATTGCCGATGGCAACTGTAGAAATTGAAGTCCAAAATCAGTA TTTGACGATTATCCGTTCTGGTAAAGCTGAATTTAATCTAAACGGACTGGAT GCTGATGAATATCCGCACTTGCCGCAGATTGAAGAGCATCATGCGATTCAGA TCCCAACTGATTTGTTAAAAAATCTAATCAGACAAACAGTATTTGCAGTGTC CACCTCAGAAACACGCCCTATCTTGACAGGTGTAAACTGGAAAGTGGAGCA AAGTGAATTATTATGCACTGCAACGGATAGCCACCGTCTTGCATTAAGAAAG GCGAAACTTGATATTCCAGAAGACAGATCTTATAACGTCGTGATTCCGGGAA AAAGTTTAACTGAACTCAGCAAGATTTTAGATGACAACCAGGAACTTGTAGA TATCGTCATCACAGAAACCCAAGTTCTGTTTAAAGCGAAAAACGTCTTGTTC TTCTCACGGCTTCTGGACGGGAATTATCCAGACACAACCAGCCTGATTCCGC AAGACAGCAAAACAGAAATCATTGTGAACACAAAAGAATTCCTTCAGGCCAT TGATCGTGCATCTCTTTTAGCTAGAGAGGGACGCAACA DNA
The Central Dogma
Hybridization A A A T T G G C C T A T G A T G C C A A A T T G G C C T A T G A T G C C
Introduction to Microarrays
Microarrays - The Concept Measure the level of transcript from a very large number of genes in one go CELL RNA
Microarrays - The Technologies Stanford Microarrays Affymetrix
Why? RNA
How? gene specific DNA probes labeled target gene mRNA
Stanford Microarrays
Coating glass slides Deposition of probes Post-processing Hybridization
Coating 1. Rinse of slides:NaOH and EtOH 2. Wash with water 2 h - shaking 3. Coat slides:poly-L-lycine 1 h - shaking 4. Wash and dry
Making Microarrays 1. Produce probes 2. Print by the use of a robot oligos cDNA library PCR products
Spotting - Mechanical deposition of probes
16-pin microarrayer
Microarrayer
Making Microarrays 1. Produce probes 2. Print by the use of a robot oligos cDNA library PCR products 3. Post-process: rehydrate snap dry UV-cross link block surface
Sample preparation 1. Design experiment Question? Replicates? Test? 2. Perform experiment 4. Label RNA Amplification? Direct or indirect? Label? wild type mutant 3. Precipitate RNA Eukaryote/prokaryote? Cell wall?
mRNA cDNA Cy3-cDNACy5-cDNA SAMPLE CONTROL Stanford microarrays DESIGN and ORDER PROBES
Affymetrix GeneChip ® oligonucleotide array 11 to 20 oligonucleotide probes for each gene On-chip synthesis of 25 mers ~ genes per chip good quality data – low variance
Catalog Arrays Human Mouse Rat Arabidopsis C. elegans Canine Drosophila E. coli P. aeruginosa Plasmodium/Anopheles Vitis vinifera (Grape) Xenopus laevis Yeast Zebrafish NimbleExpress™ Array Program
Fluidic Station and Scanner
The Affymetrix Genechip ®
TTT T T T T T T T A A A A A A A AAA Photolithography in situ synthesis Spacers bound to surface with photolabile protection groups Mask #1 Mask #2
Photolithography - Micromirrors NimbleExpress™ Array Program
Oligonucleotide Synthesis Detritylisation (Deblock A solution) O O B P N CEO NPPOC Oxidation (Oxidizer) O O B O O B P O CEOO NPPOC Addition (Amidite) O O B O O B P O CEO NPPOC Photo-Deprotection (Deblock L) O O B P N CEO NPPOC
Capping of uncoupled amidites O O B O O B P O CEOO NPPOC O O B O O B P O CEOO O O B O O B P O CEOO O O B O O B P O CEOO O O B O O B P O CEOO HO
The Affymetrix GeneChip ® A gene is represented like this: - Perfect Match (PM) - MisMatch (MM) PM MM PM: CGATCAATTGCACTATGTCATTTCT MM: CGATCAATTGCAGTATGTCATTTCT
The Technologies - Costs - Flexibility - Data Quality Affymetrix Spotter
Facility setup: Stanford Microarrays < 100,000 USD Affymetrix< 250,000 USD The Technologies - Cost Cost pr. array Stanford Microarrays USD Affymetrix USD NimbleExpress™ Array Program - a bit more expensive
NimbleExpress™ Array Program - 282,000 unique features (probes) - Design fee: 3,000 USD USD/array (minimum 10) - few weeks before delivery - can be run on the Affymetrix equipment
The Technologies - Flexibility Stanford microarrays: Are flexible, but new probes must be ordered each time Affymetrix arrays: Are not flexible, unless you order the NimbleExpress™ chip
The Technologies - Data Quality Reproducibility of data: (Pearson’s correlation coefficient) Stanford microarrays: Affymetrix: 0.95
The Technologies - Choice of Stanford microarrays: If you work with unsequenced species Low budget Affymetrix: Only sequenced species High data quality
Analysis of Data Normalization: Linear or non-linear
Is it worth it? Number of known positives Number of significantly affected genes Qspline normalization Linear normalization Known positives versus the total number of significantly affected genes at 5 different cutoffs in the TnrA experiment
Analysis of Data Normalization: Linear or non-linear Statistical test: student’s t-test ANalysis Of VAriance (ANOVA) Analysis: Principle Component Analysis (PCA) Clustering and visualization
Break - 15 minuttes After break: - introduce yourself - why are you here?