What is the Difference Between Genotyping and Sequencing

The main difference between genotyping and sequencing is that genotyping is the process of determining the genetic makeup by determining the DNA sequence of an individual, whereas sequencing is the process of determining the nucleic acid sequence.

Genotyping and sequencing are two techniques that involve the DNA sequence of an individual. Both techniques determine the changes in the DNA sequence of an individual.

Key Areas Covered

1. What is Genotyping
    – Definition, Characteristics, Importance
2. What is Sequencing
    – Definition, Characteristics, Importance
3. Similarities Between Genotyping and Sequencing
    – Outline of Common Features
4. Difference Between Genotyping and Sequencing
    – Comparison of Key Differences

Key Terms

Genotyping, Sequencing

What is Genotyping

Genotyping is the determination of the various genotypes of individuals. Therefore, this technique determines the differences in the DNA sequences between individuals. Genotyping reveals the alleles of the individual inherited from parents. Generally, the genotype of an individual is the DNA sequence of a particular location of the genome of an individual. The collection of genotypes determines the characteristics of an individual. Different individuals also have different genotypes. 

Figure 1: SNP Genotyping

Furthermore, genotyping is the laboratory procedure for the identification of the variation of DNA sequences. The common methods of genotyping include restriction fragment length polymorphism (RFLP), random amplified polymorphic detection (RAPD), amplified fragment length polymorphism (AFLP), DNA sequencing, PCR, allele-specific oligonucleotide probes, DNA microarray, and hybridization.

What is Sequencing

DNA sequencing is the determination of the nucleic acid sequence of a particular DNA piece. Generally, the first more rapid DNA sequencing method was developed by Frederick Sanger in 1977. This method was also known as ‘DNA sequencing with chain-terminating inhibitors. However, another DNA sequencing method was developed by Walter Gilbert and Allan Maxam in 1973. This method was known as ‘DNA sequencing by chemical degradation.’ In general, both methods were identified as first-generation DNA sequencing methods.

Figure 2: Sequencing

Moreover, high-throughput sequencing methods called ‘Next-generation sequencing’ or ‘second-generation sequencing methods’ were developed in the mid to late 1990s. These methods allowed the ‘massive parallel’ sequencing through the automation of the process. In addition, they allow the sequencing of whole genomes at once.

Similarities Between Genotyping and Sequencing

• Genotyping and sequencing are two techniques that deal with the DNA sequence of a particular individual.
• Moreover, DNA sequence is the nucleic acid sequence of a piece of DNA.

Difference Between Genotyping and Sequencing

Definition

Genotyping refers to a laboratory process in which an individual’s germline DNA is analyzed for specific nucleotides or bases to determine whether certain variants are present, while sequencing refers to the process of determining the nucleic acid sequence – the order of nucleotides in DNA.

Significance

Genotyping determines the differences in the DNA sequences of individuals while sequencing determines the DNA sequence of organisms.

Techniques

The main techniques in genotyping include RFLP, PCR, DNA sequencing, etc. while the main techniques in sequencing include PCR amplification.

Sequence Variants

Genotyping searches for known sequence variants while sequencing searches for both known and unknown variants.

Amount of Data Obtained

Moreover, genotyping obtains less amount of data while sequencing obtains a high amount of data.

Importance

Genotyping is important for population-based studies and for studying complex and polygenic disorders while sequencing is important for the diagnosis of diseases, mutations, and exome study.

Cost

Genotyping is cheap while sequencing is costly.

Examples

Examples of genotyping are FISH, DNA microarray, and SNP array, while examples of sequencing include Sanger sequencing and exome sequencing.

Conclusion

In brief, genotyping and sequencing are two techniques that deal with the DNA sequence of a particular individual. In genotyping, the differences in genotypes between individuals are determined while sequencing is the determination of the DNA sequence of an organism. Genotyping is important in population-based studies and the determination of diseases while sequencing is important in diagnosing diseases and mutations. Therefore, the main difference between genotyping and sequencing is the importance of each technique.

References:

1. Nan Pazdernik. “What Is Genotyping?: IDT.” Integrated DNA Technologies.
2. “DNA Sequencing.” National Human Genome Research Institute,

Image Courtesy:

1. “SNP-Dash-1updated” By Bot – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Radioactive Fluorescent Seq” By Abizar- Own Work (CC BY-SA 3.0) via Commons Wikimedia