Genotyping

Genotyping is the comprehensive process of identifying the variations in the genetic composition, or genotype, of an individual. This is achieved by assessing the individual's DNA sequence and contrasting it with a reference sequence or another individual's sequence. The primary focus of genotyping is to pinpoint the specific alleles inherited from parental genes. Although it doesn't generally delve into the specific genes of an individual, genotyping utilizes DNA sequences to demarcate biological populations through advanced molecular tools.

Methods of Genotyping

A multitude of methods have been developed over the years to perform genotyping, including:

• RFLPI: A technique that focuses on the identification of genomic DNA.
• Random Amplified Polymorphic Detection (RAPD): Another method for the detection of genomic DNA.
• AFLPD: Targets the detection of genomic DNA fragments.
• PCR: A method employed to amplify DNA sequences.
• DNA sequencing: Directly determines the order of nucleotides in DNA.
• ASO probes: Are used to detect specific sequences in DNA.
• Hybridization to DNA microarrays or beads: An approach to identify sequences by seeing if they bind to complementary strands fixed in an array.

It's imperative to acknowledge that with our current technological prowess, genotyping is often partial. This means that only certain sections of an individual’s genetic makeup are typically identified. However, the advent of new mass-sequencing technologies are on the horizon and are expected to offer whole-genome genotyping, or whole genome sequencing, in the near future.

Applications of Genotyping

Medical Research

In the realm of medical research, genotyping plays a pivotal role in the identification of genes and gene variants associated with diseases.

Microorganisms

Microorganisms, including viruses and bacteria, can also be genotyped. This is instrumental in epidemiological studies, especially when there's a need to control the spread of pathogens or trace the genesis of outbreaks. The study of genotyping within this domain is often characterized as molecular epidemiology or forensic microbiology.

Human Genotyping

Humans can be subjected to genotyping for various purposes. For example, in cases requiring paternity or maternity verification, scientists generally need to examine only a small fraction of the human genome, specifically around 10 to 20 genomic regions, like SNPs. The entirety of the human genome comprises roughly three billion nucleotides.

Transgenic Organisms

In the context of transgenic organisms, oftentimes, only a singular genomic region needs to be investigated to ascertain the genotype. For instance, when genotyping a transgenic mouse, which serves as a preferred mammalian model for medical research, a lone PCR assay is typically sufficient.

See Also

• Mendelian error
• Quantitative trait locus
• SNP genotyping

External links

• International HapMap Project
• UCLA Genotyping Core
• resources for genotyping microorganisms
• Custom snp genotyping