TPR4 Antibody

Here’s a structured FAQ collection for TPR antibody research, synthesized from peer-reviewed studies and technical documentation:

How do I validate TPR antibody specificity in my experimental system?

Validation requires a multi-step approach:

• Western Blot (WB): Confirm band size matches predicted molecular weight (~270 kDa ). Use lysates from Tpr-depleted cells (via siRNA ) to verify loss of signal.

• Immunofluorescence (IF): Compare staining patterns in siRNA-treated vs. control cells (e.g., nuclear pore localization ).

• Orthogonal validation: Pair with a second antibody targeting a non-overlapping TPR epitope .

What are optimal conditions for TPR antibody in chromatin-associated studies?

• Fixation: Use 4% PFA for IF to preserve nuclear pore architecture .

• Antigen Retrieval: For IHC, TE buffer (pH 9.0) outperforms citrate buffer .

• Dilution Ranges:

  Application	Dilution	Compatible Cell Lines
  WB	1:500–1:2000	HeLa, HEK-293
  IF/ICC	1:50–1:500	U-2 OS, HeLa

How to resolve contradictions in TPR localization across studies?

Discrepancies often arise from:

• Cell Cycle Phase: Tpr redistributes during mitosis; synchronize cells before IF .

• Stress Conditions: Under replication stress (e.g., hydroxyurea), Tpr forms nuclear aggregates .

• Antibody Clonality: Polyclonal antibodies (ab84516) may detect isoforms missed by monoclonals .

Methodological Fix:

• Include cyclin A staining to control for cell cycle stage .

• Pre-treat with transcription inhibitors (e.g., cordycepin) to isolate replication stress effects .

Can TPR antibodies differentiate between functional protein states in DNA repair?

Yes, but requires functional assays:

• Replication Stress Model: Treat cells with aphidicolin (0.2 μM, 48 hr) and quantify 53BP1 foci colocalization .

• Crosslinking IP: Use formaldehyde fixation to capture transient Tpr-DNA repair factor interactions .

• Comet Assay Correlation: Neutral vs. alkaline conditions distinguish DSBs from transcription-associated breaks .

How to address cross-reactivity with TprK variants in pathogen studies?

The TprK antigen (e.g., in Treponema pallidum) shares epitopes with human TPR . Mitigate via:

• Epitope Mapping: Use antibodies targeting non-V regions (e.g., ab84516’s C-terminal epitope ).

• Preabsorption: Incubate antibody with recombinant TprK V6 peptide before IF .

Data Example:

• LaFond et al. showed ≤15% cross-reactivity between human TPR and TprK V6 antibodies after peptide blocking .

What controls are critical when studying TPR in autoimmune contexts?

• Negative Controls:

  • Sera from non-autoimmune donors .

  • siRNA-treated cell lysates in WB .

• Positive Controls:

  • HeLa cells with endogenous replication stress .

  • Testis tissue (high TPR expression ).