Antigen KI-67 ELISA Kit (MKI67)

INTENDED USE

Human antigen KI-67 ELISA kit can measure concentrations of MKI67 (antigen KI-67, Ki-67, TSG126, KIA) present is plasma, serum, biological fluids or tissue homogenate samples.

INTRODUCTION

Antigen KI-67 represents a nuclear protein universally expressed among actively proliferating cells, but nearly undetectable in quiescent cells. Its identification emerged in 1983 when researchers derived a monoclonal antibody from mice immunized with Hodgkin lymphoma nuclei. This antibody detected a nuclear target antigen in proliferating cells, hence termed Ki-67 after the researchers’ city of origin. Despite ubiquitous use today as a clinical proliferation marker, the protein itself took over 20 additional years to isolate and characterize.

Molecular cloning reveals a large multi-domain protein containing 16 concatenated “Ki-67 repeats” split by linker regions. Within the nucleus, it dynamically associates with condensed chromosomes during mitosis, but relocates to the nucleolus periphery in interphase – mediating ribosome RNA synthesis critical for proliferation. Still the necessity of Ki-67 for cell cycle progression went unproven until genetic knockout approaches became possible in the 2000s. Strikingly Ki-67 null mice display severe atrophy in self-renewing organs caused by impaired progenitor cell division.

Today immunohistochemistry using Ki-67 antibodies to score proliferative activity sees ubiquitous use in cancer pathology. However, emerging strategies blocking Ki-67 transcription or splicing show early promise in reducing proliferation of tumor cells and self-renewing stem cells without toxicity. As the crucial role of Ki-67 enabling cell proliferation becomes ever clearer, therapeutic targeting of this multifaceted nuclear protein continues gaining increased attention.

CONTENT

All reagents supplied need to be stored at 2 °C – 8 °C, unopened reagents will retain reactivity until expiration date. Do not use reagents beyond this date.

• One 96-Well Plate: Pre-coated with anti- MKI67.
• Standards: Lyophilized recombinant.
• Sample/Standard Dilution Buffer.
• Biotinylated-labelled Antibody.
• Antibody Dilution Buffer.
• HRP-Streptavidin Conjugate (SABC).
• SABC Dilution Buffer.
• TMB Substrate.
• Wash Buffer (25x).
• Plate Sealer.
• Product Instructions.

TYPICAL RESULTS

For this antigen KI-67 ELISA kit, it is recommended that a standard curve is generated for each assay carried out.

Standard Curve: 0, 0.312, 0.625, 1.25, 2.5, 5, 10, 20 ng/ml
Reactivity: Human
Sensitivity: 0.188 ng/ml
Range: 0.313 – 20 ng/ml
Principle: Sandwich, Double Antibody
Application: Research Use Only.

ASSAY CHARACTERISTICS

– Specificity: Highly specific for MKI67, no cross reactivity or interference between MKI67 and analogues was detected.
– Recovery: Serum (88 – 105%), EDTA Plasma (86 – 102%), Heparin Plasma (86 – 96%).
– Linearity: Serum (87 – 92%), EDTA Plasma (84 – 95%), Heparin Plasma (81 – 97%).
– Precison Intra-Assay: CV < 8%
– Precison Inter-Assay: CV < 10%

REFERENCES

1. The cell proliferation antigen Ki-67 organises heterochromatin. Elife. (2016) 5: e13722. Sobecki M., et al.
2. The Biomarker Ki-67: Promise, Potential, and Problems in Breast Cancer. Appl Immunohistochem Mol Morphol. (2023) 31 (7): 478-484. Gown AM.
3. The Ki-67 antigen in the new 2021 World Health Organization classification of lung neuroendocrine neoplasms. Pathologica. (2021) 113 (5): 377-387. Pelosi G. and Travis W.D.
4. Ki-67 regulates global gene expression and promotes sequential stages of carcinogenesis. Proc Natl Acad Sci U S A. (2021) 118 (10): e2026507118. Mrouj K., et al.

ADDITIONAL INFORMATION

• Full Name: Antigen KI-67 ELISA Kit (MKI67)
• Reactivity: Human
• Sample Type: Plasma, Tissue Homogenates, Serum, Biological Fluids
• Sensitivity: 0.188 ng/ml

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