difference between genotyping and sequencing ?

Question

[2001linana]

I hope this is not a naive question. I was a bit curious about the meaning of genotyping. From wiki, I got the following. "Genotyping is the process of determining differences in the genetic make-up (genotype) of an individual by examining the individual's DNA sequence using biological assays and comparing it to another individual's sequence or a reference sequence." And then "A genotype is an organism’s set of heritable genes that can be passed down from parents to offspring." I thought this is more like standard sequencing procedure / goal, only that genotyping / genotype has a larger picture, is this understanding correct?

[igor]

The term "genotyping" can have slightly differing meanings depending on the context. There is the original biological definition that you already found.

High-throughput labs may run genotyping arrays to confirm the genetic identity of their samples and identify sample swaps. In that context, "genotyping" would refer to that whole process, so that would be more like a standard procedure.

Answer 1

[swbarnes2]

Genotyping generally means you are assessing a pre-determined subset of nucleotides. This might be a small number, or a couple million (out of say, a 3 billion human genome). Genotyping tends to be cheaper, but you only get what you are looking at. Your "genotype" would be the set of results at each point you genotyped. 23andMe usually does genotyping. They look at a few million sites known to be variable. In general, they don't do the whole genome.

Sequencing implies that you are getting every base pair, either of the whole genome, or at least a targeted region. You can find unexpected deviations from the reference, but they can be harder to process than genotyping, which tends to be yes/no at each locus.