cell line

with leap-in transposase®

ATUM's Leap-In transposases and synthetic transposons enable a cost-effective, easily implemented cell line development workflow. The technology delivers high productivity pools and cell lines, resulting in consistent product quality. The Leap-In technology underpins ATUM's cell line development services and is also licensable for your in-house use.


With Leap-In technology generate highly productive stable pools. Pool titers are very predictive of the titers of final clonal lines.


Exceptional genetic stability leads to stable productivity of Leap-in-generated clonal cell lines. Derisk your downstream process development, scale-up and manufacturing.


Product quality and productivity are highly comparable between stable pools and derivative clones. Initiate analytical development, process development, and GLP toxicology studies early, shaving months off the CMC timeline.


Cell line development using Leap-In technology is less labor intensive and does not require automation. Many cell line development projects may be conducted simultaneously by a small team.

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Leap-In Transposases Integrate Intact DNA Constructs into Active Chromatin

Leap-In transposases integrate single copies of the entire synthetic transposon into multiple transcriptionally active genomic loci. Expression constructs integrated by Leap-In transposases do not exhibit the rearrangements and concatemerization that are common, problematic hallmarks of random non-homologous recombination driven integrations. Maintaining structural integrity of the sequence integrated into the host genome ensures that regulatory elements remain associated with the appropriate open reading frames, and desired balances between multiple open reading frames are maintained.

How Leap-In Transposase Works


A synthetic transposon, comprising the expression construct and selection marker, flanked by inverted terminal repeats (ITRs).


Leap-In transposase recognizes its specific ITRs, binds and excises the transposon.


Leap-In transposase recognizes 4-base insertion sites across the host cell genone.


The intact transposon is inserted at up to 59 loci across the genome.

Expression Balancing and Optimization with VectorGPS®

The balance of expression for each subunit in a multi-subunit protein affects productivity and product quality. Compounding this complexity, there is often an incomplete correlation between the best ratios of transiently transfected genes, and the optimal stable expression of each subunit. Using our VectorGPS® design platform, we can design, synthesize and transfect several synthetic transposons in parallel, each harboring up to 4 independently-controlled, codon-optimized ORFs with altered expression ratios. Stable pool productivity and product quality analyses will reveal the optimal construct.

Leap-In Transposon
2 ORFs


Leap-In Transposon
3 ORFs


Leap-In Transposon
4 ORFs


Control of protein subunit expression ratios in 2-, 3- and 4-ORF Leap-In transposons.


Our Hosts

ATUM currently uses two host cell lines with lineage traceability and documented provenance, are adapted to commercially-available chemically-defined serum-free formulations. No raw materials of animal origin are used during our CLD process.

- HD-BIOP3 GS null CHOK1 cell line from Horizon Discovery
- DG44 from the lab of Dr. Lawrence Chasin (Columbia University)

Stable Pool Selection

Leap-In transposase is very efficient. Most cells that are transfected with Leap-In transposons and transposase will integrate multiple copies of the transposon into their genomes. This results in rapid recovery of stable pools consisting of many very similar cells. This means that the productivity and product quality of clones derived from these pools are similar to the pools themselves. Process and analytical development can therefore start as early as a few weeks post-transfection. Material for toxicology studies can be prepared from stable pools to further shorten overall CMC timelines.


Product Quality

Product quality (glycan relative abundance %, charge %) and productivity is comparable between stable pool and derivative clones.

Clone Isolation

In stable pools generated by Leap-In technology, the clonal distributions within the pools are strongly biased towards high productivity. This reduces the number of clones that need to be tested to at most a few hundred.

166 clones

Static 96 well plate


22 clones

24 deep-well scale, 7 day fed batch clone ranking


8 clones

Highest ranked clones, 125 ml shake, 14 day fed batch


Screening, characterizing and ranking fewer clones eliminates the need to invest in expensive, high-throughput instrumentation and allows more cell line development projects to be managed simultaneously.

Stability Testing

Leap-In transposase mRNA is co-transfected with the synthetic transposon into the cell. The mRNA is translated and the Leap-In transposase protein acts to integrate the transposon into the host genome. Once the transposase mRNA has been degraded through the normal cellular RNA turnover pathways, there is no way for the cell to generate transposase to mobilize the transposon, so the integration structures are stably maintained. Because each integration contains a single copy of the transposon, there is no instability resulting from concatemer recombination or repeat-induced silencing.

Clonal cell lines are grown for 60 populations doublings then assayed for genetic stability by ddPCR, and productivity stability. The majority of clones created using Leap-In technologies exhibit no significant decreases in their volumetric productivity and integrated transposon copy number.

Productivity maintained

Copy number maintained

Pie charts show the maintenance of productivity and transposon copy number in clonal cell lines after 60 population doublings. Data is taken from 47 clones created using Leap-In technologies. All clones retained at least 70% of their initial productivity and transposon copy number.


1 - 3 weeksDESIGN & SYNTHESIS OFOPTIMIZED SYNTHETICTRANSPOSONGene synthesis & vector constructionPool generation & characterizationProtein (mg)6 - 9 weeksISOLATE, CHARACTERIZEAND RANKSTABLE CLONESCell line generation4 - 5 weeksRCB MANUFACTURING& RELEASEStable poolClonal cell lineRCBBEGIN PROCESS DEVELOPMENT & ANALYTICAL DEVELOPMENT Protein (g)~9- 10 weeksGENETIC STABILITY STUDIES60 PDProtein (g)(Clone derived)Monoclonality established (VIPS, Solentim)RCB & Stability studies4 - 6 weeksESTABLISHMENT & CHARACTERIZATION OF HIGHLY PRODUCTIVEREPRESENTATIVE STABLE POOLS

Licensing leap-in

Bring the advantages of Leap-In technology to your in-house cell line development. We offer three tiers of licensing to meet your research and commercialization needs. Under all licenses, Leap-In transposase mRNA and synthetic transposon DNA are purchased from ATUM. Genes and vectors designed and synthesized by ATUM.


Test and optimize the Leap-In technology in your labs. Convert to a full research license after 6 months.


Annual license fee. Access to all new transposon and transposase technology developed at ATUM.


Payable on cell lines that enable commercialization of your therapeutic, diagnostic or product. Pay annually, as a single lump sum, or attached to clinical milestones.

Have a question?
Let's talk.

ATUM customer support scientists are available to discuss cloning strategies, gene design constraints, bioinformatics analyses, and other molecular biology/biotechnology concerns.


Corporate Headquarters
(Newark, California)
+1 650 853 8347

European Office
(Basel, Switzerland)
+41 (0) 61 262 0212


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