In genetic engineering, floxing refers to the insertion of a DNA sequence (which is then said to be floxed) between two LoxP sequences, creating an artificial gene cassette which can then be conditionally deleted (knocked out), translocated, or inverted in a process called Cre-Lox recombination. [1]

Unlock the power of the Cre/lox system for tissue-specific, inducible knockouts and advanced gene tracking in mouse models. Learn practical breeding schemes to simplify complexity, refine gene expression control, and avoid lethal phenotypes.

In principle, one mouse must have a tissue-specific driven cre gene and another mouse have loxP flanked (floxed) alleles of interest gene Y. Expression of Cre recombinase excises floxed loci and inactivates the gene Y. Cre- loxP system is a widely used powerful technology for …

You’ve created mice that carry a Cre-conditional (“floxed”) allele in your target gene. You’ve bred them with mice that should express Cre in your target tissue. Here we go over the four essential steps you need to take to validate your tissue-specific KO model, and the reasons why you may still detect protein expression.

Nov 1, 2022 · Conditional knockout mice are used as part of a system that’s commonly referred to as “Cre-lox” which names the two elements that make it work. “Cre” is Cre recombinase, a DNA modifying enzyme originally derived from a virus. This enzyme seeks out DNA with a specific sequence known as a “lox” site.

Aug 11, 2017 · Conditional knockout using Cre/lox is essential for functional analysis of genes. CRISPR/Cas in combination with two sets of guide RNAs and a single-stranded oligonucleotide enables...

May 19, 2006 · Two of the most exciting and versatile genetic tools designed in the last 30 years are the Cre-lox and FLP-FRT technologies. Both allow the location and timing of gene expression to be closely regulated. This article briefly outlines …

The resulting mice contain the floxed (flanked by loxP sites) allele in all tissues but are phenotypically wildtype. These floxed mice are then bred to Cre expressing transgenic animals, wherein the promoter used to drive Cre expression will determine the site of the gene deletion.

The Cre enzyme identifies pairs of loxP sites (arrowheads), which flank (flox) the DNA, and catalyzes reciprocal DNA recombination between the two sites to excise a small piece of DNA.

What if there is no floxed founder? We look for founders with high percentage of loxP insertion at one site and comparably high percentage indels at the other site, see examples below in red rectangles.