What is the difference between VNTR and STR?
Just want to know the difference, thanks :)
- 1 decade agoFavorite Answer
Short Tandem Repeat sequences (STRs) are similar to VNTRs in that they involve tandem repeats of a core sequence in variable numbers among the population to produce a polymorphic distribution. The major difference is that the core sequence is usually only 3 or 4 nucleotides in length (VNTR core sequences can be 16 or more nucleotides). Usually a tighter range of alleles results. The small size of the STRs used in forensic DNA profiling (amplimers range from 100 - 500 bp) allows for more efficient amplification by PCR and also allows the use of DNA that has been degraded more significantly because even small pieces of DNA may contain intact STR sites. Primers are designed to anneal to sequences in the DNA that flank the STR. PCR Amplification of the material between the primer locations includes the STR region. Therefore, any allelic differences between individuals will be evidenced by different lengths for the amplification product among individuals tested.