Restriction Fragment Length polymorphism (RFLP) refers to the difference in homologous DNA sequences detected from the fragments that has been digested into different lengths by the restriction enzyme. It is a common and inexpensive technique to process genetic analysis by using the restriction enzyme to digest the DNA sequence into smaller pieces in order to view the digested fragments (probes) through electrophoresis separation based on the sizes of the fragments. Sometimes the process requires PCR to amplify the small fragment to be visible on the fragments analysis after the separation step.

The RFLP are frequently used in genome mapping and in variation analysis such as genotyping, forensics, localization of genes for genetic disorders, paternity tests, SNPs detecting, determination of risk for disease, and hereditary disease diagnostics, etc.

Using Qsep100 DNA fragment analyzer the result of how DNA being digested by restriction enzyme into different fragment length can easily be seen on the electrophoretogram below.


            Figure 1: This electrophoretogram shows the result of DNA being digested into different fragments by restriction enzyme.


Figure 2:  Qsep100 highlights the restriction map of pBR322-Mspl digestion.

i) dfDNA fragments shorter than 67bp can be clearly monitored by Qsep100 but not traditional agarose electrophoresis. (15 bp concentration= 0.069 ng/ml)
ii) dsDNA with different sequences but same size, 169/160 bp and 147/147 bp can be well resolved in two peaks.
iii) DNA fragments of 238 bp and 242 bp can be separated into two isolated peaks.