Microarray analysis for analyzing gene-expression patterns in a tissue

Tissue sample 1. Itolme l mHNA mHNA molecules V 2. Make cDNA by reverse transcription, u g flumelcenlly labeled nucleol es 4“ , y Labeled cDNA molecules V g(:’ (Single slrands) a. Hybridiutio Awly me anA mixture lo a DNA mlcrolrrly Segmenl of a microarray Fixed to each spol on \\ DNA strand a microarray are millions Microanay (chip) of copies of short single-slranded DNA molecules, 3 different gene in each spel on microarray V 4. Rinse ofl excess cDNA. pm the micmarray in a scanner lo measure fluorescence ol each spoL cDNA hybridized lo Fluuroxecnce inianlily Indlenlee the amaum oi DNA on microarray mnNA expresled in me dune sample Readuul Scanner No fluorescence: gene ncl expressed in tissue sample Moderale fluorescence: low gene expression Brighl fluorescence: h hly expressed gene in tissue sample