PPP3R1 Mouse mAb: Protocol & Application Guide

PPP3R1 Mouse mAb is a high-specificity monoclonal antibody targeting the regulatory subunit B of calcineurin (PPP3R1), validated for use in immunological and cell-signaling research applications including Western blot, immunohistochemistry, and immunofluorescence.

Product SKU

Ab349215

Antibody Type

Mouse Monoclonal Antibody (mAb)

Target Protein

PPP3R1 (Calcineurin regulatory subunit B, isoform 1)

Host Species

Mouse

Recommended Applications

Western Blot (WB), Immunohistochemistry (IHC), Immunofluorescence (IF)

Storage

Store at -20°C; avoid repeated freeze-thaw cycles

Overview of PPP3R1 and Antibody Background

PPP3R1 encodes the regulatory subunit B (also known as calcineurin B, type 1) of calcineurin, a calcium- and calmodulin-dependent serine-threonine phosphatase. Calcineurin is a heterodimer composed of a catalytic subunit A (PPP3CA, PPP3CB, or PPP3CC) and a regulatory subunit B (PPP3R1 or PPP3R2). The regulatory subunit B is an EF-hand calcium-binding protein that is essential for phosphatase activity and plays a pivotal role in calcium-dependent signal transduction pathways, including T-cell activation via the NFAT transcription factor family.

PPP3R1 Mouse mAb (Ab349215) is produced using standard hybridoma technology and provides high specificity for detection of endogenous PPP3R1 protein across a range of experimental platforms. This antibody is a valuable tool for researchers studying immune signaling, neuronal function, cardiac hypertrophy, and other calcineurin-mediated processes.

Sample Preparation Protocol

Cell Lysates (for Western Blot):

1. Wash cells twice with ice-cold phosphate-buffered saline (PBS, pH 7.4).
2. Lyse cells in RIPA buffer [50 mM Tris-HCl (pH 7.4), 150 mM NaCl, 1% NP-40, 0.5% sodium deoxycholate, 0.1% SDS] supplemented with protease inhibitor cocktail and phosphatase inhibitors.
3. Incubate on ice for 30 minutes with occasional vortexing.
4. Centrifuge at 12,000 × g for 15 minutes at 4°C. Collect supernatant.
5. Quantify protein concentration using BCA or Bradford assay.
6. Prepare samples in Laemmli sample buffer and boil at 95°C for 5 minutes prior to loading.

Tissue Sections (for IHC/IF):

1. Fix tissue in 10% neutral buffered formalin for 24 hours, then process and embed in paraffin (FFPE) or use fresh-frozen sections.
2. For FFPE sections: perform antigen retrieval using citrate buffer (10 mM sodium citrate, pH 6.0) in a heat-induced epitope retrieval (HIER) step at 95–100°C for 20 minutes.
3. Block endogenous peroxidase (for IHC) with 3% H₂O₂ in methanol for 10 minutes.
4. Block non-specific binding with 5% normal serum (matched to secondary antibody host) in PBS-T (0.1% Tween-20) for 1 hour at room temperature.

Antibody Incubation and Detection Protocol

Western Blot (WB):

1. Separate 20–40 µg of total protein by SDS-PAGE on an appropriate percentage gel (recommend 12% for PPP3R1, expected molecular weight ~19 kDa).
2. Transfer proteins to a PVDF or nitrocellulose membrane.
3. Block membrane with 5% non-fat dry milk in TBST (20 mM Tris, 150 mM NaCl, 0.1% Tween-20, pH 7.6) for 1 hour at room temperature.
4. Incubate membrane with PPP3R1 Mouse mAb (Ab349215) at the manufacturer-recommended dilution (refer to product datasheet; typically 1:500–1:2000) overnight at 4°C with gentle agitation.
5. Wash membrane 3× with TBST, 10 minutes each.
6. Incubate with appropriate HRP-conjugated anti-mouse secondary antibody for 1 hour at room temperature.
7. Wash 3× with TBST, 10 minutes each.
8. Detect signal using ECL chemiluminescence substrate and image on X-ray film or digital imaging system.

Immunohistochemistry (IHC):

1. After blocking, incubate sections with PPP3R1 Mouse mAb (Ab349215) at recommended dilution overnight at 4°C in a humidified chamber.
2. Wash 3× with PBS-T.
3. Apply appropriate biotinylated secondary antibody or polymer-based detection system.
4. Develop with DAB (3,3′-diaminobenzidine) substrate; counterstain with hematoxylin.
5. Dehydrate, clear, and mount sections with permanent mounting medium.

Immunofluorescence (IF):

1. After blocking, incubate cells or sections with PPP3R1 Mouse mAb at recommended dilution for 1 hour at room temperature or overnight at 4°C.
2. Wash 3× with PBS-T.
3. Incubate with fluorophore-conjugated anti-mouse secondary antibody for 1 hour at room temperature, protected from light.
4. Counterstain nuclei with DAPI (0.1–1 µg/mL) for 5–10 minutes.
5. Wash and mount with aqueous mounting medium. Image by fluorescence or confocal microscopy.

Troubleshooting Guide

Problem	Possible Cause	Suggested Solution
No signal on Western blot	Antibody dilution too high; insufficient protein loaded; transfer failure	Optimize dilution; load 30–50 µg protein; verify transfer with Ponceau S staining
High background	Inadequate blocking; secondary antibody cross-reactivity; insufficient washing	Increase blocking time to 2 hours; use 5% BSA instead of milk for phospho-targets; increase wash steps
Multiple non-specific bands	Protein degradation; over-exposure	Add fresh protease inhibitors to lysis buffer; reduce ECL exposure time
Weak IHC signal	Over-fixation; insufficient antigen retrieval; antibody dilution too high	Optimize fixation time; extend HIER step; titrate antibody concentration downward
High background in IF	Inadequate blocking; non-specific secondary antibody binding	Increase blocking concentration to 10% serum; include 0.1% Triton X-100 for permeabilization if targeting intracellular antigen

Storage, Handling and Quality Assurance

Storage Conditions: PPP3R1 Mouse mAb (Ab349215) should be stored at -20°C upon receipt. For short-term use (up to 1 month), the antibody may be kept at 4°C. Avoid repeated freeze-thaw cycles, as this may compromise antibody integrity and reduce binding activity. Aliquoting the antibody upon first use is strongly recommended.

Handling: Centrifuge the vial briefly before opening to ensure all material is at the bottom of the tube. Work on ice when preparing dilutions. Do not use antibody that has been left at room temperature for extended periods or appears turbid.

Quality Control: Each lot of PPP3R1 Mouse mAb is subject to quality control testing to confirm specificity and reactivity. Lot-specific data are provided with each shipment. Researchers should always refer to the current product datasheet for the most up-to-date dilution recommendations and validated applications, as these may vary between lots.

Frequently asked questions

What is the expected molecular weight of PPP3R1 detected by this antibody?

PPP3R1 (calcineurin regulatory subunit B, isoform 1) has a predicted molecular weight of approximately 19 kDa. On Western blot, the band may appear at or near this size, though post-translational modifications can occasionally cause slight shifts in apparent molecular weight.

Which species does PPP3R1 Mouse mAb (Ab349215) cross-react with?

Specific cross-reactivity data should be confirmed by consulting the product datasheet for Ab349215. PPP3R1 is highly conserved across mammalian species, so reactivity toward human, mouse, and rat samples is commonly observed for antibodies targeting this protein, but this must be verified lot-by-lot.

Can this antibody be used for immunoprecipitation (IP) or flow cytometry?

The source material for Ab349215 does not explicitly list immunoprecipitation or flow cytometry as validated applications. Researchers interested in these applications should contact Aladdin Scientific technical support or perform optimization experiments, and should refer to the current product datasheet for the full list of validated applications.

How should I determine the optimal antibody dilution for my experiment?

Always start with the dilution range recommended in the Ab349215 product datasheet. If background is high, increase the dilution (use less antibody); if signal is weak, decrease the dilution (use more antibody). Performing a dilution series (e.g., 1:500, 1:1000, 1:2000) in a pilot experiment is the most reliable approach to identify the optimal working concentration for your specific sample type and detection system.

What positive control is recommended when using PPP3R1 Mouse mAb?

Cell lines or tissues known to express calcineurin, such as brain tissue, T lymphocytes, or cardiac muscle, are commonly used as positive controls for PPP3R1 detection. Consult the Ab349215 datasheet for any lot-specific recommended positive control cell lines or tissues.

References

1. Klee CB, Ren H, Wang X. Regulation of the calmodulin-stimulated protein phosphatase, calcineurin. J Biol Chem. 1998;273(22):13367-13370.
2. Crabtree GR, Olson EN. NFAT signaling: choreographing the social lives of cells. Cell. 2002;109(Suppl):S67-79.
3. Rusnak F, Mertz P. Calcineurin: form and function. Physiol Rev. 2000;80(4):1483-1521.

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.