research use only

CD4 Antibody [D18N16]

Catalog No.: F4645

    Application: Reactivity:
    • F4645-wb
      Lane 1: HuT 102

    Usage Information

    Dilution
    1:1000
    1:50
    1:50 - 1:200
    Application
    WB, IP, IF
    Reactivity
    Human
    Source
    Rabbit Monoclonal Antibody
    Storage Buffer
    PBS, pH 7.2+50% Glycerol+0.05% BSA+0.01% NaN3
    Storage (from the date of receipt)
    -20°C (avoid freeze-thaw cycles), 2 years
    Predicted MW
    55 kDa
    Positive Control HuT 102 cell
    Negative Control Mouse spleen; PC-3 cell; Ramos cell

    Exprimental Methods

    WB
    Experimental Protocol:
     
    Sample preparation
    1. Tissue: Lyse the tissue sample by adding an appropriate volume of ice-cold RIPA/NP-40 Lysis Buffer (containing Protease Inhibitor Cocktail),and homogenize the tissue at a low temperature.
    2. Adherent cell: Aspirate the culture medium and wash the cells with ice-cold PBS twice. Lyse the cells by adding an appropriate volume of RIPA/NP-40 Lysis Buffer (containing Protease Inhibitor Cocktail) and put the sample on ice for 5 min.
    3. Suspension cell: Transfer the culture medium to a pre-cooled centrifuge tube. Centrifuge and aspirate the supernatant. Wash the cells with ice-cold PBS twice. Lyse the cells by adding an appropriate volume of RIPA/NP-40 Lysis Buffer (containing Protease Inhibitor Cocktail) and put the sample on ice for 5 min.
    4. Place the lysate into a pre-cooled microcentrifuge tube. Centrifuge at 4°C for 15 min. Collect the supernatant;
    5. Remove a small volume of lysate to determine the protein concentration;
    6. Combine the lysate with protein loading buffer. Boil 20 µL sample under 95-100°C for 5 min. Centrifuge for 5 min after cool down on ice.
     
    Electrophoretic separation
    1. According to the concentration of extracted protein, load appropriate amount of protein sample and marker onto SDS-PAGE gels for electrophoresis. Recommended separating gel (lower gel) concentration: 10%. Reference Table for Selecting SDS-PAGE Separation Gel Concentrations
    2. Power up 80V for 30 minutes. Then the power supply is adjusted (110 V~150 V), the Marker is observed, and the electrophoresis can be stopped when the indicator band of the predyed protein Marker where the protein is located is properly separated. (Note that the current should not be too large when electrophoresis, too large current (more than 150 mA) will cause the temperature to rise, affecting the result of running glue. If high currents cannot be avoided, an ice bath can be used to cool the bath.)
     
    Transfer membrane
    1. Take out the converter, soak the clip and consumables in the pre-cooled converter;
    2. Activate PVDF membrane with methanol for 1 min and rinse with transfer buffer;
    3. Install it in the order of "black edge of clip - sponge - filter paper - filter paper - glue -PVDF membrane - filter paper - filter paper - sponge - white edge of clip";
    4. The protein was electrotransferred to PVDF membrane. ( 0.45 µm PVDF membrane is recommended ) Reference Table for Selecting PVDF Membrane Pore Size Specifications
    Recommended conditions for wet transfer: 200 mA, 120 min.
    ( Note that the transfer conditions can be adjusted according to the protein size. For high-molecular-weight proteins, a higher current and longer transfer time are recommended. However, ensure that the transfer tank remains at a low temperature to prevent gel melting.)
     
    Block
    1. After electrotransfer, wash the film with TBST at room temperature for 5 minutes;
    2. Incubate the film in the blocking solution for 1 hour at room temperature;
    3. Wash the film with TBST for 3 times, 5 minutes each time.
     
    Antibody incubation
    1. Use 5% skim milk powder to prepare the primary antibody working liquid (recommended dilution ratio for primary antibody 1:1000), gently shake and incubate with the film at 4°C overnight;
    2. Wash the film with TBST 3 times, 5 minutes each time;
    3. Add the secondary antibody to the blocking solution and incubate with the film gently at room temperature for 1 hour;
    4. After incubation, wash the film with TBST 3 times for 5 minutes each time.
     
    Antibody staining
    1. Add the prepared ECL luminescent substrate (or select other color developing substrate according to the second antibody) and mix evenly;
    2. Incubate with the film for 1 minute, remove excess substrate (keep the film moist), wrap with plastic film, and expose in the imaging system.
    IF
    Experimental Protocol:
     
    Sample Preparation
    1. Adherent Cells: Place a clean, sterile coverslip in a culture dish. Once the cells grow to near confluence as a monolayer, remove the coverslip for further use.
    2. Suspension Cells: Seed the cells onto a clean, sterile slide coated with poly-L-lysine.
    3. Frozen Sections: Allow the slide to thaw at room temperature. Wash it with pure water or PBS for 2 times, 3 minutes each time.
    4. Paraffin Sections: Deparaffinization and rehydration. Wash the slide with pure water or PBS for 3 times, 3 minutes each time. Then perform antigen retrieval.
     
    Fixation
    1. Fix the cell coverslips/spots or tissue sections at room temperature using a fixative such as 4% paraformaldehyde (4% PFA) for 10-15 minutes.
    2. Wash the sample with PBS for 3 times, 3 minutes each time.
     
    Permeabilization
    1.Add a detergent such as 0.1–0.3% Triton X-100 to the sample and incubate at room temperature for 10–20 minutes.
    (Note: This step is only required for intracellular antigens. For antigens expressed on the cell membrane, this step is unnecessary.)
    Wash the sample with PBS for 3 times, 3 minutes each time.
     
    Blocking
    Add blocking solution and incubate at room temperature for at least 1 hour. (Common blocking solutions include: serum from the same source as the secondary antibody, BSA, or goat serum.)
    Note: Ensure the sample remains moist during and after the blocking step to prevent drying, which can lead to high background.
     
    Immunofluorescence Staining (Day 1)
    1. Remove the blocking solution and add the diluted primary antibody.
    2. Incubate the sample in a humidified chamber at 4°C overnight.
     
    Immunofluorescence Staining (Day 2)
    1. Remove the primary antibody and wash with PBST for 3 times, 5 minutes each time.
    2. Add the diluted fluorescent secondary antibody and incubate in the dark at 4°C for 1–2 hours.
    3. Remove the secondary antibody and wash with PBST for 3 times, 5 minutes each time.
    4. Add diluted DAPI and incubate at room temperature in the dark for 5–10 minutes.
    5. Wash with PBST for 3 times, 5 minutes each time.
     
    Mounting
    1. Mount the sample with an anti-fade mounting medium.
    2. Allow the slide to dry at room temperature overnight in the dark.
    3. Store the slide in a slide storage box at 4°C, protected from light.
     
    IF
    Experimental Protocol:
     
    Specimen Preparation 
    1. Aspirate liquid, then cover cells to a depth of 2–3 mm with 4% Paraformaldehyde diluted in 1X PBS.
    NOTE: Paraformaldehyde is toxic, use only in a fume hood.
    2. Fix cells for 15 min at room temperature.
    3. Aspirate fixative, rinse three times in 1X PBS for 5 min each.
    4. Proceed with Immunostaining.
     
    Immunostaining
    1. Add theblocking buffer and incubate for 60 min at RT.
    2. Prepare primary antibody diluent in antibody dilution buffer as recommended .
    3. Aspirate blocking solution, apply diluted primary antibody.
    4. Incubate overnight at 4°C.
    5. Rinse three times in 1X PBS for 5 min each.
    6. Incubate specimens in fluorochrome-conjugated secondary antibody diluted in antibody dilution buffer for 1–2 hr at room temperature in the dark.
    7. Rinse three times in 1X PBS for 5 min each.
    8. Mount slides usingmounting medium with DAPI and cover with coverslips.
    9. For best results, allow mountant to cure overnight at room temperature. For long-term storage, store slides flat at 23°C protected from light.
     

    Datasheet & SDS

    Biological Description

    Specificity
    CD4 Antibody [D18N16] detects endogenous levels of total CD4 protein.
    Subcellular Location
    Cell membrane, Membrane
    Uniprot ID
    P01730
    Clone
    D18N16
    Synonym(s)
    T-cell surface glycoprotein CD4; T-cell surface antigen T4/Leu-3; CD4
    Background
    Cluster of Differentiation 4 (CD4) is a type I integral membrane glycoprotein and a member of the immunoglobulin superfamily, characterized by four extracellular Ig-like domains (D1-D4) responsible for ligand binding, a transmembrane region, and a cytoplasmic tail that recruits intracellular signaling molecules such as the tyrosine kinase Lck essential for T cell activation. The extracellular D1 domain of CD4 interacts specifically with the non-polymorphic β2 domain of MHC class II molecules, facilitating co-recognition alongside the T cell receptor (TCR) for antigen presentation. CD4 stabilizes and prolongs TCR-MHC interactions, enabling the phosphorylation of immunoreceptor tyrosine activation motifs (ITAMs) by Lck and subsequent downstream signaling cascades leading to T cell activation, cytokine production, and immune response modulation. CD4 is mostly expressed on T helper cells, regulatory T cells, monocytes, macrophages, and dendritic cells. CD4 serves as the primary receptor for HIV-1 entry into host cells through gp120 envelope glycoprotein binding. Post-translational modifications such as palmitoylation enhance CD4 localization in lipid rafts, optimizing signal transduction efficiency.
    References
    • https://pubmed.ncbi.nlm.nih.gov/18035040/
    • https://pubmed.ncbi.nlm.nih.gov/31001252/

    Tech Support

    Answers to questions you may have can be found in the inhibitor handling instructions. Topics include how to prepare stock solutions, how to store inhibitors, and issues that need special attention for cell-based assays and animal experiments.

    Handling Instructions

    Tel: +1-832-582-8158 Ext:3
    If you have any other enquiries, please leave a message.

    * Indicates a Required Field

    Please enter your name.
    Please enter your email. Please enter a valid email address.
    Please write something to us.