Definition SNPs

SNPs (Single Nucleotide Polymorphisms) are single base pair changes in the genome that can differ between individuals. These sequence variations are located on known positions in the human DNA. To act as a genetic marker, one condition is required. The less frequent base pair is present in 1% of the human population. Almost all common SNPs have only two alleles. The genomic distribution of SNPs is not homogenous. SNPs usually occur in non-coding regions more frequently than in coding regions. Variations in the DNA sequences of humans can affect how humans develop diseases and respond to pathogens,  chemicals, drugs, vaccines and other agents.


SNP typing

In the past, SNP detection methods were very intensive and time consuming. Currently, the techniques evolved to partly automated methods. This evolution is due to new genome technologies. An example of such a technique is the sequenom IPLEX. This technique is based on primer extensions. An oligonucleotide primer attaches in front of a SNP position and a single nucleotide will be incorporated on the SNP position. Via MALDI-TOF mass spectometry, the mass of the elongated primer will be measured. This result is related to SNP identification.

The Illumina Chips and Affymetrix SNP arrays are two micro array applications for genotyping on high resolution level. They both offer multiple platforms to satisfy the customers’ needs. The chosen platform depends on the research question and information of an amount of genome wide SNPs is obtained.



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