Thermo Fisher Scientific p21 Recombinant Rabbit Monoclonal Antibody (ZR288), RAbMono

Applications

Tested Dilution

Publications

Immunohistochemistry (Paraffin) (IHC (P))

Ready-to-use 150-200 µL

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Product Specifications

Species Reactivity

Human

Host/Isotype

Rabbit / IgG

Expression System

CHO cells

Class

Recombinant Monoclonal

Type

Antibody

Clone

ZR288

Immunogen

Purified human recombinant fusion p21 protein

Conjugate

Unconjugated Unconjugated Unconjugated

Form

Liquid

Purification

Protein A

Storage buffer

tris with BSA, NP-40

Contains

<0.1% sodium azide

Storage conditions

4° C

Shipping conditions

Wet ice

Product Specific Information

This product is diluted and in a ready-to-use formulation.

A recommended positive control tissue for this product is Colon adenocarcinoma, however positive controls are not limited to this tissue type.

The primary antibody is intended for laboratory professional use in the detection of the corresponding protein in formalin-fixed, paraffin-embedded tissue stained in manual qualitative immunohistochemistry (IHC) testing. This antibody is intended to be used after the primary diagnosis of tumor has been made by conventional histopathology using non-immunological histochemical stains.

This MAb recognizes a 21 kDa protein, identified as the p21WAF1 tumor suppressor protein. This MAb is highly specific to p21 and shows no cross-reaction with other closely related mitotic inhibitors. p21WAF1 is a specific inhibitor of cdk`s and a tumor suppressor involved in the pathogenesis of a variety of malignancies. The expression of this gene acts as an inhibitor of the cell cycle during G1 phase and is tightly controlled by the tumor suppressor protein p53. Its expression is induced by the wild type, but not mutant, p53 suppressor protein. Normal cells generally display a rather intense nuclear p21 expression. Loss of p21 expression has been reported in many carcinomas (gastric carcinoma, non-small cell lung carcinoma, thyroid carcinoma).

Antibody is used with formalin-fixed and paraffin-embedded sections. Pretreatment of deparaffinized tissue with heat-induced epitope retrieval or enzymatic retrieval is recommended. In general, immunohistochemical (IHC) staining techniques allow for the visualization of antigens via the sequential application of a specific antibody to the antigen (primary antibody), a secondary antibody to the primary antibody (link antibody), an enzyme complex and a chromogenic substrate with interposed washing steps. The enzymatic activation of the chromogen results in a visible reaction product at the antigen site. Results are interpreted using a light microscope and aid in the differential diagnosis of pathophysiological processes, which may or may not be associated with a particular antigen.

A positive tissue control must be run with every staining procedure performed. This tissue may contain both positive and negative staining cells or tissue components and serve as both the positive and negative control tissue. External Positive control materials should be fresh autopsy/biopsy/surgical specimens fixed, processed and embedded as soon as possible in the same manner as the patient sample (s). Positive tissue controls are indicative of correctly prepared tissues and proper staining methods. The tissues used for the external positive control materials should be selected from the patient specimens with well-characterized low levels of the positive target activity that gives weak positive staining. The low level of positivity for external positive controls is designed to ensure detection of subtle changes in the primary antibody sensitivity from instability or problems with the staining methodology. A tissue with weak positive staining is more suitable for optimal quality control and for detecting minor levels of reagent degradation.

Internal or external negative control tissue may be used depending on the guidelines and policies that govern the organization to which the end user belongs to. The variety of cell types present in many tissue sections offers internal negative control sites, but this should be verified by the user. The components that do not stain should demonstrate the absence of specific staining, and provide an indication of non-specific background staining. If specific staining occurs in the negative tissue control sites, results with the patient specimens must be considered invalid.

Target Information

Protein p21 is a tumor suppressor protein which is an inhibitor of Cyclin-dependent kinases (CDK) and is transcriptionally activated by p53. P21 is important in the response of cells to genotoxic stress and a major transcriptional target of p53 protein. The occurrence of p21 in the nucleus executes binding and inhibition activity of cyclin dependent kinases Cdk1 and Cdk2, and blocks the transition from G1 phase into S phase or from G2 phase into mitosis after DNA damage, which enables the repair of damaged DNA. In the cytoplasm, p21 protein has an anti-apoptotic effect. P21 is able to bind to and inhibit caspase 3, as well as the apoptotic kinases ASK1 and JNK. P21 exhibits a dual function in carcinogenesis, and acts as a tumor suppressor, prevents apoptosis, and acts as an oncogene.

For Research Use Only. Not for use in diagnostic procedures. Not for resale without express authorization.