Anti-Mouse CD28 [Clone E18] — Purified in vivo GOLD™ Functional Grade

Based on the search results, clone E18 refers to different antibody clones used in distinct mouse studies, each serving specific experimental purposes.

Anti-Bcl-XL Antibody Clone E18

The most well-documented E18 clone is an anti-Bcl-XL antibody that is used extensively in mouse research. This rabbit monoclonal antibody detects the Bcl-XL protein, which is a potent inhibitor of cell death that prevents apoptosis by blocking voltage-dependent anion channels and regulating mitochondrial function. In mouse studies, this antibody is employed for:

• Western blotting to detect Bcl-XL protein levels
• Flow cytometry for intracellular and surface detection
• Immunohistochemistry in tissue sections
• Immunofluorescence for cellular localization studies
• Immunoprecipitation experiments

The antibody has been validated across multiple species including mouse, rat, and human samples, making it particularly valuable for comparative studies. With over 230 publications citing its use, this clone has proven reliable for investigating apoptosis, mitochondrial function, and cell survival mechanisms in various mouse disease models.

Anti-CD28 Antibody Clone E18

There is also reference to an anti-mouse CD28 clone E18 used as a purified functional-grade antibody. However, the search results indicate that a different CD28 clone (D665) is more commonly used for in vivo mouse studies. The D665 clone serves as a CD28 superagonist that induces expansion of regulatory T cells (Tregs) in various mouse disease models. CD28 is a costimulatory receptor that, when activated, induces IL-2 production and T cell proliferation.

Developmental Biology Applications

In developmental studies, the term "E18" often refers to embryonic day 18 rather than a specific clone. At this developmental stage, researchers study cell lineage tracing in the cerebral cortex, where clonally related cells migrate radially during perinatal development.

The specific application of clone E18 in your studies would depend on which antibody system you're referencing and the particular biological pathway you're investigating in your mouse model.

The correct storage temperature for sterile packaged clone E18 (an anti-Dengue E protein monoclonal antibody) is 4°C for short-term storage and -20°C or -80°C for long-term storage.

For details:

• Short-term storage (days to a few weeks): Store at 4°C in a refrigerator.
• Long-term storage (months to years): Aliquot the antibody and store at either -20°C or -80°C. This helps maintain stability and avoids loss of binding activity.
• Avoid repeated freeze-thaw cycles to prevent protein denaturation and activity loss.

These guidelines are typical for monoclonal antibodies and specifically confirmed for clone E18.

Commonly used antibodies or proteins that are employed with or alongside E18 (depending on context, either as a developmental stage—embryonic day 18—or as an antibody such as for NCAM or CD28) in the literature often depend on the precise biological focus:

If E18 refers to the antibody recognizing the exon 18-encoded region of NCAM (Neural Cell Adhesion Molecule):

• Other monoclonal antibodies developed for NCAM include MUM-1, MUM-4, and MUM-6, which target the E18 region and are used together in assays such as ELISAs to identify and quantify the presence of this moiety, especially in studies of small cell lung cancer (SCLC). An additional antibody, MUMi-21B2, is also used as a capture antibody in ELISA systems aimed at quantifying E18.
• For characterizing extracellular vesicles (EVs) from SCLC, RNL-1 and 123C antibodies (recognizing the extracellular moiety of NCAM) are also used in conjunction with E18 antibodies for immunoaffinity capture and subsequent detection.

If you are referring to clone E18 as an antibody specific to other proteins:

• Clone E18 is reported as a monoclonal antibody specific to mouse CD28, often used in flow cytometry and immunohistochemistry studies. In such contexts, it is commonly used with markers such as CD3, CD4, CD8 for T cells, and sometimes with activation or inhibitory markers.

If your focus is on E18 as a developmental stage (e.g., embryonic day 18 mouse/rat brain or tissue):

• Common markers used in studies at this stage would be neural or lineage-specific proteins and antibodies depending on the organ system studied. For example, in neural development studies at E18, antibodies to NCAM, Bcl-XL, OCT4, SOX17, BLIMP1, and various cytoskeletal or transcription factors are regularly used. In addition, markers such as GATA4, GATA6, PDGFRA, and APOA1 have been identified as commonly co-expressed in lineage tracing with embryonic markers during early development.

Summary Table

If you clarify whether you mean the E18 antibody/epitope or the embryonic stage, more context-specific recommendations can be provided.

Based on the scientific literature, clone E18 has been referenced in several distinct research contexts, each with significant findings in different fields of biomedical research.

NCAM Biomarker Research

E18 has been extensively studied as part of the Neural Cell Adhesion Molecule (NCAM) system, where it represents the exon 18 encoded protein moiety. This component has emerged as a crucial biomarker for small cell lung cancer (SCLC). Researchers have successfully developed three monoclonal antibodies specifically targeting E18 to improve SCLC diagnosis and enable personalized treatment approaches. The E18 antigen was expressed in E. coli using his-tagged proteins and used to immunize mice for hybridoma production.

Fetal Development and Wound Healing

In developmental biology research, E18 refers to embryonic day 18, a critical timepoint in fetal development. Comparative studies between E14 and E18 fetal fibroblasts revealed dramatic changes in gene expression patterns that correspond to the transition from scarless healing to scar-forming wound repair.

Gene Expression Changes:

• 245 genes were significantly upregulated at E18 compared to E14
• 30 genes were significantly downregulated during this developmental transition

Key Pathway Alterations:The upregulated pathways in E18 fibroblasts included colorectal cancer metastasis signaling, hepatic fibrosis/hepatic stellate cell activation, pancreatic adenocarcinoma signaling, platelet-derived growth factor (PDGF) signaling, and endometrial cancer signaling. Conversely, downregulated pathways involved putrescine biosynthesis III, s-adenosyl-l-methionine biosynthesis, and various inositol biosynthesis pathways.

Antiviral Antibody Development

Clone E18 has been utilized in the development of novel bispecific antibodies against enterovirus A71 (EVA71). Researchers created an innovative IgG-like bispecific antibody called E18-F1 by fusing an EVA71-specific single-domain antibody (F1) to the C-terminus of the E18 IgG light chain. This bispecific design demonstrated enhanced binding activity and improved antiviral efficacy compared to the original individual antibodies.

Herpesvirus Genome Cloning

In virology research, clone E18 has been used for complete herpesvirus genome cloning. Sequencing analysis revealed that clone E18 contained the complete RCMV-E genome without any deletions or insertions. The clone exhibited high sequence fidelity with only three polymorphisms in non-coding regions and five substitutions in coding regions, one of which was silent.

Clinical and Research Implications

These findings across multiple research domains highlight E18's versatility as both a biomarker and research tool. The NCAM E18 biomarker research offers potential for improved cancer diagnostics, while the developmental studies provide insights into regenerative medicine applications. The bispecific antibody work demonstrates E18's utility in antiviral therapeutic development, and the viral cloning applications show its reliability for genomic research.

The consistent appearance of E18 across these diverse scientific applications underscores its importance in advancing our understanding of cancer biology, developmental processes, antiviral strategies, and viral genomics.