Design a Western Blot for SERBP1

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 four isoforms. Relative to the canonical sequence, isoforms 2 and 4 lack residues 203–208; isoforms 3 and 4 lack residues 233–247. These are UniProt canonical coordinates. Check whether the antibody epitope is retained in each isoform before interpreting additional bands; the sequence differences do not establish where each isoform will run.

PTM · UniProt assigns phosphorylation of SERBP1 Ser199 and Thr226 to MTOR, using canonical sequence coordinates. When comparing conditions that affect MTOR activity, measure total SERBP1 alongside a site-specific phospho signal if suitable reagents are available. A change in phosphorylation does not necessarily produce a visible band shift.

UniProt lists additional phosphoserines, acetyllysines and methylarginines. For example, Ser197, Ser203 and Ser205 are listed as phosphorylated, Lys68 as acetylated and Arg165 as methylated; positions use UniProt canonical coordinates. These features support checking modification-sensitive antibody recognition, but do not by themselves identify the cause of an extra band.

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 A04755-2 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 · The supplied observations place SERBP1 near 55 kDa in human blots and 50 kDa in mouse or rat blots, versus a predicted 45 kDa. UniProt lists alternative splicing and multiple modified residues, but these features alone do not establish the cause of the apparent mass difference. Use the observed position as a guide and validate band identity independently.

SERBP1 occurs in the cytoplasm and nucleus and associates with mature 80S ribosomes. Use the same extraction and fractionation procedure across samples, and compare equivalent fractions with appropriate loading controls. If a phospho-specific signal is measured, compare it with total SERBP1 from the same samples.

First check whether the bands are consistent across samples and recognized by an independent SERBP1 antibody. Consider the four isoforms and their specified deletions when checking epitope coverage. UniProt also lists numerous modified residues, but their presence alone cannot assign an unexpected band to a particular modification or explain its mobility.

UniProt places SERBP1 in the cytoplasm, nucleus and perinuclear region, and reports association with mature 80S ribosomes. When comparing blots, record whether samples are whole-cell lysates or subcellular fractions and keep preparation consistent. A difference between fractions may reflect SERBP1 distribution as well as abundance.