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Anti-phospho-Chk1(Ser345) Antibody, clone 3D14 ZooMAb® Rabbit Monoclonal

newenhanced validation

recombinant, expressed in HEK 293 cells

Quality Level

biological source



expressed in HEK 293 cells

antibody form

purified antibody

antibody product type

primary antibodies


3D14, recombinant monoclonal


recombinant, expressed in HEK 293 cells

product line

ZooMAb® learn more



mol wt

calculated mol wt 54.43 kDa
observed mol wt ~55 kDa

purified by

using Protein A

species reactivity

mouse, human, monkey

species reactivity (predicted by homology)

canine, feline, porcine


antibody small pack of 25 μL

enhanced validation

recombinant expression
Learn more about Antibody Enhanced Validation


affinity binding assay: suitable
immunocytochemistry: suitable
western blot: suitable



epitope sequence

C-terminal half



Protein ID accession no.

UniProt accession no.

shipped in


storage temp.


General description

ZooMAb® antibodies represent an entirely new generation of recombinant monoclonal antibodies.Each ZooMAb® antibody is manufactured using our proprietary recombinant expression system, purified to homogeneity, and precisely dispensed to produce robust and highly reproducible lot-to-lot consistency. Only top-performing clones are released for use by researchers. Each antibody is validated for high specificity and affinity across multiple applications, including its most commonly used application. ZooMAb® antibodies are reliably available and ready to ship when you need them.


Clone 3D14 is a ZooMAb® Rabbit recombinant monoclonal antibody that specifically detects Serine/threonine-protein kinase Chk1 phosphorylated on serine 345.


KLH-conjugated linear peptide corresponding to 11 amino acids surrounding phosphoserine 345 from the C-terminal half of human Serine/threonine-protein kinase Chk1


Quality Control Testing

Evaluated by Western Blotting in lysate from HeLa cells treated with Etoposide.

Western Blotting Analysis: A 1:1,000 dilution of this antibody detected Serine/Threonine-protein kinase Chk1 phosphorylated on Ser345 in lysate from HeLa cells overnight serum starved and treated with Etoposide (20 μg/ml), but not in lysate from untreated cells.

Tested applications

Western Blotting Analysis: A 1:1,000 dilution from a representative lot detected phospho-Chk1 (Ser345) in COS-1 and NIH3T3 cells treated with UV lighrt.

Immunocytochemistry Analysis: A 1:100 dilution from a representative lot detected phospho-Chk1 (Ser345) in HeLa cells treated with UV light (50 mJ UV w/1hr recovery).

Affinity Binding Assay: A representative lot of this antibody bound phosphorylated Chk1 with a KD of 3.0 x 10-6 in an affinity binding assay.

Note: Actual optimal working dilutions must be determined by end user as specimens, and experimental conditions may vary with the end user
Anti-phospho-Chk1 (Ser345), clone 3D14 ZooMAb®, Cat. No. ZRB1424, is a recombinant Rabbit Monoclonal antibody that detects Chk1 phosphorylated on Ser345 and is tested in Affinity Binding Assay, Immunocytochemistry, and Western Blotting.

Target description

Serine/threonine-protein kinase Chk1 (UniProt: O14757; also known as EC:, CHK1 checkpoint homolog, Cell cycle checkpoint kinase, Checkpoint kinase-1) is encoded by the CHEK1 (also known as CHK1) gene (Gene ID: 1111) in human. Chk1 is a serine/threonine-protein kinase that is required for checkpoint-mediated cell cycle arrest. It is expressed ubiquitously, and its most abundant expression is observed in thymus, testis, small intestine, and colon. It is activated through phosphorylation predominantly by ATR but also by ATM in response to DNA damage or inhibition of DNA replication. It may also negatively regulate cell cycle progression during unperturbed cell cycles that is achieved by a number of mechanisms that together help to preserve the integrity of the genome. Chk1 recognizes the substrate consensus sequence [R-X-X-S/T]. It binds to and phosphorylates CDC25A (at Ser 178, Thr 507) and CDC25C (at Ser 216). These phosphorylations create binding sies for 14-3-3- proteins, which inhibit CDC2A and CDC2C. Phosphorylation of Chk1 on serine 345 induces a change in the conformation of the protein that activates the kinase activity and is shown to be a prerequisite for interaction with FBXO6 and subsequent ubiquitination at lysine 436. Phosphorylation at serine 345 increases its binding to 14-3-3 proteins and promotes its nuclear retention. Conversely, dephosphorylation at serine 345 by protein phosphatase, Mg2+/Mn2+ dependent 1D (PPM1D) contributes to exit from checkpoint mediated cell cycle arrest. The activated, serine 345 phosphorylated form can undergo polyubiquitination at lysine 436 and undergo degradation ensuring that activated Chk1 does not accumulate as cells progress through S phase. This ZooMAb® recombinant monoclonal antibody, generated by our propriety technology, offers significantly enhanced specificity, affinity, reproducibility, and stability over conventional monoclonals. Ref.: Moiseeva, TN., et al. (2019). Proc. Natl. Acad. Sci. USA. 116(27); 13374-13383; Chen, MS., et al. (2003). Mol. Cell Biol. 23(21); 7488-7497).

Physical form

Purified recombinant rabbit monoclonal antibody IgG, lyophilized in PBS with 5% Trehalose, normal appearance a coarse or translucent resin. The PBS/trehalose components in the ZooMAb® formulation can have the appearance of a semi-solid (bead like gel) after lyophilization. This is a normal phenomenon. Please follow the recommended reconstitution procedure in the data sheet to dissolve the semi-solid, bead-like, gel-appearing material. The resulting antibody solution is completely stable and functional as proven by full functional testing. Contains no biocide or preservatives, such as azide, or any animal by-products. Larger pack sizes provided as multiples of 25 μL.


300 μg/mL after reconstitution at 25 μL per vial. Please refer to guidance on suggested starting dilutions and/or titers per application and sample type.

Storage and Stability

Recommend storage of lyophilized product at 2-8°C; Before reconstitution, micro-centrifuge vials briefly to spin down material to bottom of the vial; Reconstitute each vial by adding 25 μL of filtered lab grade water or PBS; Reconstituted antibodies can be stored at 2-8°C, or -20°C for long term storage. Avoid repeated freeze-thaws.

Legal Information

ZooMAb is a registered trademark of Merck KGaA, Darmstadt, Germany


Unless otherwise stated in our catalog or other company documentation accompanying the product(s), our products are intended for research use only and are not to be used for any other purpose, which includes but is not limited to, unauthorized commercial uses, in vitro diagnostic uses, ex vivo or in vivo therapeutic uses or any type of consumption or application to humans or animals.

Storage Class Code

13 - Non Combustible Solids



Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Certificate of Analysis

Certificate of Origin

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