I am new to this. I have an SNP array composed of digits [0,1,2] for chromosome 21. How do I find the start:end locations for the region that is "21q22.11" step by step?
You first need to get the coordinates of the "cytoband" 21q22.11, which I would search for using the UCSC table browser. You need the following settings: Clade: Mammal genome: Human assembly: group: Mapping and Sequencing track: Chromosome Band table: cytoBand region: position chr21 output format: BED
(you can leave other options as default)
That will give you a bed file of cytobands on chr21. You'll need to search (e.g. grep) for your cytoband: q22.11.