The clones labelled as “Knockout first” are expected to contain all the loxP sites as shown in the allele map. The knockout is obtained by introduction of a splice acceptor/reporter- cassette with a strong polyA site into an endogenous intron upstream of a critical exon. Should this allele be exposed to Flpase it is expected to revert to expressing wild type protein; upon subsequent exposure to Cre recombinase the critical exon is expected to be deleted.

For clones labelled “Targeted, non-conditional” the 3’ loxP site has not been verified. Targeted non-conditional clones arise from the failure of the 3’ loxP site to be incorporated along with the reporter/selection cassette during the process of homologous recombination in ES cells. Targeted non-conditionals mutate genes the same way as unmodified knockout first alleles but cannot be converted into conditional alleles.

See the KB article: What is a targeted trap? Are they conditionals?