kb dna ladder  (Thermo Fisher)

Journal: Poultry Science

Article Title: Construction and modification of a low-copy plasmid-based infectious clone for GI-19 genotype IBV via Red/ET recombineering: A simplified and efficient reverse genetics system for co ronavirus

doi: 10.1016/j.psj.2026.106881

Figure Lengend Snippet: Validation of recombinant plasmids by restriction enzyme analysis and functional selection screening. (A) Restriction enzyme digestion of intermediate recombinant plasmids was performed using XhoI, XbaI , and KpnI . The observed banding patterns were consistent with the predictions generated by SnapGene software. Lanes 1–3 show the predicted digestion patterns of p15A-CmR-D90, p15A-CmR-D90-Δ5a/AmpR-ccdB, and p15A-CmR-D90-Δ5a/EGFP. Lanes 4–5, 6–7, and 8–9 correspond to the experimental digestion results of these respective plasmids. M: TaKaRa 1 kb DNA Ladder. All digested products were resolved by electrophoresis on 1% agarose gels and visualized with ethidium bromide staining. (B) Functional verification of the selection marker gene. The intermediate recombinant plasmid p15A-CmR-D90-Δ5a/AmpR-ccdB was transformed into two E. coli strains: GBred (CcdB-sensitive) and GBred- gyrA462 (CcdB-resistant). On LB agar plates containing ampicillin and chloramphenicol, only GBred- gyrA462 survived, confirming the toxicity of CcdB and functionality of the selection cassette. In the second recombination step, replacement of the AmpR-ccdB cassette by the target Δ5a/EGFP fragment yielded the final recombinant plasmid p15A-CmR-D90-Δ5a/EGFP. Upon counter-selection with CcdB, only host E. coli GBred harboring the correctly recombined plasmid survived on chloramphenicol-containing LB plates, while non-recombinant bacteria were eliminated.

Article Snippet: M: TaKaRa 1 kb DNA Ladder.

Techniques: Biomarker Discovery, Recombinant, Functional Assay, Selection, Generated, Software, Electrophoresis, Staining, Marker, Plasmid Preparation, Transformation Assay, Bacteria

Journal: STAR Protocols

Article Title: Protocol for the genome-wide identification of intrinsic transcription factor binding motifs by mammalian-optimized pull-down sequencing

doi: 10.1016/j.xpro.2026.104513

Figure Lengend Snippet: Fragmentation of genomic DNA (A) Agarose gel electrophoresis of genomic DNA before (lane 1) and after (lane 2-7) DNase I digestion with different incubation time. Successful digestion results in a smear of fragments ranging from 50 to 200 bp. M represents the DNA ladder, with numbers on the side indicating base pair in bp. (B) Electropherogram from the Agilent Bioanalyzer showing the size distribution of the DNase I-treated genomic DNA. After digestion for 3 min, 64.3% of the fragments are 50∼200 bp, and average size is 130 bp. (C) The virtual gel image corresponding to the electropherogram in (B). M represents the DNA ladder, with numbers on the left indicating base pair in bp.

Article Snippet: 1Kb DNA Ladder , Thermo Fisher Scientific , Cat#10787026.

Techniques: Agarose Gel Electrophoresis, Incubation