SAL4 Antibody

What is SALL4 and why are antibodies against it important for research?

SALL4 is a transcription factor that plays a critical role in maintaining pluripotency and self-renewal of embryonic stem cells. It contributes significantly to embryonic development and is implicated in the growth of various cancers. SALL4 expression is silenced in most adult tissues after birth (with the exception of spermatogonia), but becomes re-expressed in various solid malignancies . Antibodies against SALL4 are particularly valuable research tools because:

• They enable detection of SALL4 expression in normal and pathological tissues

• They serve as biomarkers for testicular germ cell cancers

• They allow researchers to study the role of SALL4 in pluripotency maintenance

• They help track changes in SALL4 expression during developmental processes and cancer progression

What is the molecular structure of SALL4 protein?

SALL4, also known as Zinc finger protein 797, contains 7 C2H2-type zinc fingers that mediate its function as a transcription factor. The calculated molecular weight of SALL4 is 112 kDa (1053 amino acids), though the observed molecular weight in experimental conditions typically ranges from 66-75 kDa . This discrepancy between calculated and observed weight is important for researchers to note when interpreting western blot results.

What are the different isoforms of SALL4 and how do they differ?

SALL4 exists in multiple isoforms, with SALL4-A representing the whole, full-length isoform. While the complete repertoire of SALL4 isoforms and their specific functions remain incompletely characterized, research indicates that different isoforms may have distinct expression patterns and roles in development and disease . The pattern of expression and specific role of each isoform is still being investigated, highlighting the need for isoform-specific antibodies in research contexts.

What are the main applications for SALL4 antibodies in cancer research?

SALL4 antibodies serve multiple critical functions in cancer research:

• Diagnostic biomarker: SALL4 has been established as a precise biomarker for testicular germ cell cancers

• Tumor classification: Helps distinguish between different types of germ cell tumors

• Cancer progression studies: Enables tracking of SALL4 expression changes during malignant transformation

• Therapeutic target assessment: Facilitates evaluation of SALL4 as a potential therapeutic target

The high sensitivity and specificity of SALL4 antibodies for detecting cancer cells make them valuable tools for both research and potential clinical applications.

What experimental techniques commonly employ SALL4 antibodies?

SALL4 antibodies have been validated for multiple experimental applications, as detailed in the following table:

How can researchers distinguish between SALL4 isoforms in experimental settings?

Distinguishing between SALL4 isoforms requires isoform-specific antibodies. Recently, researchers have developed a monoclonal antibody specifically targeting the SALL4-A isoform . This pioneering approach involved:

• Selection of a 33-mer synthetic peptide unique to SALL4-A

• Conjugation of this peptide with KLH for immunization

• Hybridoma cell generation and screening by ELISA for SALL4-A peptide reactivity

• Purification of anti-SALL4-A mAbs from ascites fluid using protein G column

• Validation of specificity through ELISA and IHC on appropriate tissue samples

This methodology enables researchers to specifically detect SALL4-A in experimental samples, which is crucial for understanding the differential roles of SALL4 isoforms in normal and pathological contexts.

What are the recommended dilutions and conditions for SALL4 antibody applications?

The optimal working dilutions for SALL4 antibodies vary by application:

For all applications, it is advised that researchers titrate the antibody in each testing system to obtain optimal results .

What antigen retrieval methods are recommended for SALL4 immunohistochemistry?

For optimal detection of SALL4 in tissue sections, antigen retrieval is crucial. The recommended protocol includes:

• Primary option: Antigen retrieval with TE buffer pH 9.0

• Alternative option: Antigen retrieval with citrate buffer pH 6.0

These conditions have been validated for detection of SALL4 in mouse testis tissue, human ovary tumor tissue, and human testis tissue . The choice between these methods may depend on the specific tissue type and fixation conditions used.

How should SALL4 antibodies be stored to maintain optimal activity?

To preserve antibody activity, SALL4 antibodies should be stored according to these specifications:

• Storage temperature: -20°C

• Buffer composition: PBS with 0.02% sodium azide and 50% glycerol at pH 7.3

• Expected stability: One year after shipment when properly stored

• Aliquoting: Unnecessary for -20°C storage

• Special considerations: Small volume preparations (20μl) may contain 0.1% BSA

Following these storage guidelines will help ensure consistent antibody performance across experiments.

How do SALL4 antibodies specifically contribute to testicular cancer research?

SALL4 has emerged as a novel and precise biomarker for testicular germ cell cancers . Recent research utilizing SALL4-A specific antibodies has demonstrated:

• High specificity for testicular cancer tissues compared to normal tissues

• Ability to detect SALL4-A in both the nucleus and cytoplasm of cancer cells

• Specific staining of spermatogonia in testicular tissue

• Negative reactivity in normal kidney, stomach, and prostate tissues

These findings highlight the potential of SALL4 antibodies, particularly isoform-specific versions, in improving diagnostic accuracy and potentially guiding therapeutic approaches for testicular cancer.

What are the challenges in developing highly specific antibodies against SALL4 isoforms?

Developing isoform-specific antibodies against SALL4 presents several challenges:

• High sequence homology between isoforms requires precise epitope selection

• Limited knowledge about the complete repertoire of SALL4 isoforms

• Need for extensive validation to confirm isoform specificity

• Technical difficulties in producing functional recombinant SALL4 proteins for screening

Despite these challenges, researchers have successfully developed specific monoclonal antibodies against the SALL4-A isoform by selecting unique peptide sequences and implementing rigorous validation protocols . This approach serves as a model for developing antibodies against other SALL4 isoforms.

What is Sal4 antibody and how does it differ from anti-SALL4 antibodies?

The Sal4 antibody (note lowercase "a") is entirely distinct from antibodies targeting the SALL4 protein. Sal4 is a well-characterized, dimeric IgA monoclonal antibody that specifically recognizes the O5-antigen of Salmonella Typhimurium (STm) lipopolysaccharide (LPS) . This antibody was originally isolated from B cell hybridomas derived from Peyer's patch tissues of mice immunized with an attenuated strain of STm .

Unlike SALL4 antibodies that target a human transcription factor, Sal4 antibody targets bacterial antigens and has potential applications in infection prevention research.

How effective is Sal4 IgA in preventing Salmonella infection in experimental models?

Research has demonstrated that Sal4 IgA is highly effective at inhibiting Salmonella invasion in experimental models. Key findings include:

• Dose-dependent reduction in STm uptake into Peyer's patch tissues

• At high doses (12 μg), Sal4 IgA produced >4 log₁₀ reduction in invasion efficiency

• Even at lower doses (0.4 μg), Sal4 IgA conferred a competitive disadvantage to O5-positive Salmonella strains

• Maximum inhibitory effect observed at concentrations above 1.2 μg

Why is the antibody isotype important for anti-Salmonella activity?

Research comparing different antibody isotypes has revealed that the effectiveness of anti-Salmonella antibodies is isotype-dependent. Studies demonstrate that:

• Orally administered monoclonal IgA and SIgA provide effective passive immunization against invasive Salmonella

• IgG antibodies with identical antigen-binding domains did not confer protection

• This difference highlights the importance of antibody structure beyond antigen recognition

This isotype-specific effect likely relates to the specialized transport mechanisms for IgA in mucosal tissues and its enhanced stability in the intestinal environment compared to IgG.