Design a Western Blot for CHEK1

Band shift · Use the separately labelled calculated mass and catalog-observed evidence above. A sequence annotation does not establish an observed migration shift. Verify target identity with orthogonal controls.

Isoforms · UniProt lists three isoforms. Relative to isoform 1, isoform 2 lacks residues 1–94 and changes residues 95–97 from RIE to MEK; isoform 3 lacks residues 412–445. These sequence differences could affect band size. Check whether the antibody recognizes a region retained in the isoform under study.

PTM · Canonical CHEK1 has a predicted mass of 54.4 kDa, consistent with the observed band near 54 kDa. UniProt lists nine phosphoserines, but their presence alone does not establish a visible shift or explain an apparent mass difference.

UniProt identifies phosphoserines at residues 317 and 345 as modified by ATM and ATR. It also lists phosphoserines at 280, 286, 296, 301, 331, 467, and 468 without assigning those enzymes. These are UniProt coordinates; verify the numbering convention used by a phosphosite antibody before interpreting its signal.

DNA damage is a relevant condition for comparison because CHEK1 is linked to DNA damage and repair, and UniProt assigns phosphorylation at residues 317 and 345 to ATM and ATR. Compare treated and matched untreated samples with a site-specific antibody; the listed features do not establish that either signal will increase under every condition.

Measure a site-specific phospho-CHEK1 signal alongside total CHEK1 in matched samples. UniProt lists multiple phosphoserines, so a change at one site should not be taken as a change at all sites or in total protein. Identify the site and use UniProt coordinates when reporting results.

Induction · No general induction response is established by this guide. A pathway or gene-set association is not evidence of induction in a particular specimen. Verify the relevant treatment and control in a target-specific experiment.

Transfer · Standard workflow guidance: verify transfer efficiency for the intended target size before interpreting a weak signal. Use total-protein assessment and optimize transfer for the membrane, gel and apparatus; the labelled catalog values take precedence.

Blocking · Standard workflow guidance: follow the A01060 datasheet where specified. Otherwise compare 5% milk or 5% BSA in TBST; for a phospho-specific assay start with BSA. Optimize background and specific signal with matched controls.

Quantitation · Standard workflow guidance: quantify only a validated target band within the linear exposure range. Use consistent sample preparation and loading, retain biological replicates, and avoid interpreting saturation or loading differences as regulation.

Interpretation · First compare them with the approximately 54 kDa observed band and the antibody’s target region. Isoform 2 lacks residues 1–94 and isoform 3 lacks 412–445, which may affect detection or apparent size. Phosphorylation is documented, but the feature list alone cannot assign an unexpected band to phosphorylation or an isoform.