2007- CRISPR provides acquired resistance against viruses in prokaryotes. (Barrangou et al., 2007)
2012- Idea of using CRISPR- Cas9 as a genome engineering tool was published by Jennifer Doudna and Emmanuelle Charpentier.
CRISPRs (clustered regularly interspaced short palindromic repeats) are DNA loci containing short repetitions of base sequences which separated by short "spacer DNA" from previous exposures to a virus or phage.
-این مطالعه در مورد اصلاح ژنتیکی بوسیله crispr/cas است که روی ژن ccr5 در جنین 3pn انجام شده است.
- انواع سیستم کریسپر
-کریسپر قسمت هایی از DNA باکتریایی هستند که شامل توالی های تکراری و SPACER لیدر و CASهستند. اینCRIISPR/CAS سیستم ایمنی پروکاریوت ها در برابر پلاسمید و فاژهاست.
- بزرگترین مزیت کریسپر نسبت به بقیه خاصیت مالتی پلکس بودن است.
The excised DNA fragments of the TCR that are not destined to be incorporated into a recombinant receptor gene are also ligated at their ends, forming a variety of circular DNA by-products called T-cell receptor excision circles (TRECs).
TREC test for SCID: On January 1, 2008, Wisconsin (USA) became the first state in the world to screen all newborns for SCID through a method based on measurement of T cell receptor excision circles (TRECs) by polymerase chain reaction (PCR), using DNA extracted from newborn dried blood spots (Guthrie cards).
TRECs were initially used to monitor generation of new T cells in HIV-infected individuals receiving effective anti retroviral treatment.
Amplify and quantify TREC DNA
Amplify and quantify reference gene DNA
Plasmids are used as standards
TaqMan Probe
- sequence specific
- fluorescent signal