Product details
Synonyms = DNA replication licensing factor MCM2, Minichromosome maintenance protein 2 homolog, Nuclear protein BM28, BM28; CCNL1; CDC like 1; cdc19; CDCL1; Cell devision cycle like 1; Cyclin like 1; DNA replication licensing factor MCM2; KIAA0030; Minichromosome maintenance complex component 2; Minichromosome maintenance deficient 2 (mitotin); Minichromosome maintenance protein 2 homolog; Mitotin; Nuclear protein BM28
Antibody type = Recombinant Rabbit monoclonal / IgG
Clone = MSVA-502R
Positive control = Colon: A strong nuclear MCM2 immunostaining should be seen in virtually all crypt base cells.
Negative control = Colon: MCM2 immunostaining should be less intense or absent in surface epithelial cells and absent in most stroma cells.
Cellular localization = Nucleus
Reactivity = Human
Application = Immunohistochemistry
Dilution = 1:100 – 1:200
Intended Use = Research Use Only
Relevance of Antibody
MCM2 is a highly sensitive marker for proliferating cells.
Biology Behind
The MCM2 gene is located at 3q21.3 and codes for a nuclear protein which belongs to the highly conserved mini-chromosome maintenance proteins (MCM) 2-7 that play a key role in genome replication. They form a ring-shaped hexameric protein complex which unwinds double-stranded DNA, forms a replication fork during the initiation of DNA replication, and helps to recruit other DNA replication related proteins. The MCM2-7 limits DNA replication to a single occurrence per cell division and is critical for maintaining genome integrity. MCM2 is phosphorylated, and thus regulated by protein kinases such as CDC2 and CDC7. The MCM proteins are expressed in all cells in the G1, S, G2 and M-phase of the cell cycle but in contrast to the better established proliferation marker Ki-67, MCMs are already expressed in early G1 phase. This results in the detection of more proliferating cells as compared to Ki67 immunohistochemistry which might be advantageous in tumor types with low proliferative activity.
Staining Pattern in Normal Tissues
Images describing the MCM2 staining pattern in normal tissues obtained by the antibody MSVA-502R are shown in our “Normal Tissue Gallery”.
| Brain | Cerebrum | Negative. |
| Cerebellum | Negative. | |
| Endocrine Tissues | Thyroid | Weak to moderate MCM2 staining of a small fraction of follicular cells. |
| Parathyroid | MCM2 staining in a small fraction of epithelial cells. | |
| Adrenal gland | A variable MCM2 staining occurs in a small fraction of adrenocortical cells. | |
| Pituitary gland | Weak MCM2 staining in a small fraction of cells (neuro- and adenohypophysis). | |
| Respiratory system | Respiratory epithelium | Significant MCM2 staining in a fraction of (mostly basal/suprabasal) respiratory epithelial cells. |
| Lung | Strong MCM2 staining of a large subset of pneumocytes. | |
| Gastrointestinal Tract | Salivary glands | Weak MCM2 staining in a fraction of epithelial cells. |
| Esophagus | Moderate to strong MCM2 staining of suprabasal and basal cells of the squamous epithelium. | |
| Stomach | Strong MCM2 immunostaining of many mucous neck cells. | |
| Duodenum | MCM2 staining predominates in epithelial cells of the crypts. Weak MCM2 staining in a fraction of epithelial cells in Brunner glands. | |
| Small intestine | MCM2 staining predominates in epithelial cells of the crypts. | |
| Appendix | MCM2 staining predominates in in epithelial cells of the crypts. Some lymphocytes are also positive. | |
| Colon | MCM2 staining predominates in in epithelial cells of the crypts. Some lymphocytes are also positive. | |
| Rectum | MCM2 staining predominates in in epithelial cells of the crypts. Some lymphocytes are also positive. | |
| Liver | MCM2 staining of variable intensity in a small fraction of hepatocytes. | |
| Gallbladder | A variable number of MCM2 positive cells can be seen in the gallbladder epithelium. | |
| Pancreas | Moderate to strong MCM2 staining in a rather small fraction of epithelial cells. | |
| Genitourinary | Kidney | Few epithelial cells are MCM2 positive. |
| Urothelium | Some (suprabasal) urothelial cells show MCM2 staining. | |
| Male genital | Prostate | MCM2 staining is more common in basal than in acinar epithelial cells. |
| Seminal vesicles | MCM2 staining of variable intensity in a rather small fraction of epithelial cells. | |
| Testis | Most spermatogonia and spermatocytes show strong MCM2 positivity. | |
| Epididymis | Significant MCM2 staining in a fraction of epithelial cells. | |
| Female genital | Breast | Strong MCM2 staining of almost all luminal cells. |
| Uterus, myometrium | Weak MCM2 staining in some muscle cells. | |
| Uterus, ectocervix | The squamous epithelium shows a moderate MCM2 immunostaining of (mostly) suprabasal cells. | |
| Uterus endocervix | Only few epithelial cells show MCM2 staining. | |
| Uterus, endometrium | Almost all epithelial cells and a fraction of stromal cells are MCM2 positive. The fraction of MCM2 positive epithelial cells is lower in the secretion phase. | |
| Fallopian Tube | Strong MCM2 staining of a significant subset of epithelial cells. | |
| Ovary | Strong MCM2 staining of a large fraction of granulosa and theca interna cells. Weak to moderate MCM2 staining of stroma cells. Weak MCM2 staining of corpus luteum cells. | |
| Placenta early | Strong MCM2 staining of a large fraction of cytotrophoblast cells. | |
| Placenta mature | Strong MCM2 staining of a large fraction of cytotrophoblast cells. | |
| Amnion | Negative. | |
| Chorion | Moderate to strong MCM2 staining in a fraction of chorion cells | |
| Skin | Epidermis | Suprabasal and basal cell layers (weaker) of the squamous epithelium show a distinct MCM2 positivity. |
| Sebaceous glands | Intense MCM2 positivity of peripheral germinative cells. | |
| Muscle/connective tissue | Heart muscle | Faint MCM2 staining of some muscle cells. |
| Skeletal muscle | Significant MCM2 staining in a large fraction of skeletal muscle cells. | |
| Smooth muscle | Faint MCM2 staining in some muscle cells. | |
| Vessel walls | Negative. | |
| Fat | Negative. | |
| Stroma | Usually negative. | |
| Endothelium | Usually negative. | |
| Bone marrow/ lymphoid tissue | Bone marrow | Moderate to strong MCM2 staining in most bone marrow cells. |
| Lymph node | Many lymphocytes are MCM2 positive. Strongest MCM2 staining occurs in most cells of germinal centres and in scattered individual cells of the interfollicular zone. | |
| Spleen | Most lymphocytes of the white pulp are MCM2 positive. A strong MCM2 positivity occurs in few scattered cells of all compartments. | |
| Thymus | Strong MCM2 positivity of most cells of the thymic cortex. | |
| Tonsil | Many lymphocytes are MCM2 positive. Strongest MCM2 staining occurs in most cells of germinal centres and in scattered individual cells of the interfollicular zone. In the tonsil crypts, many epithelial cells (basal/suprabasal) are MCM2 positive. | |
| Remarks |
MCM2 is a ubiquitously expressed protein. The findings described above are thus consistent with the RNA data described in the Human Protein Atlas (Tissue expression MCM2).
Positive control = Colon: A strong nuclear MCM2 immunostaining should be seen in virtually all crypt base cells.
Negative control = Colon: MCM2 immunostaining should be less intense or absent in surface epithelial cells and absent in most stroma cells.
Staining Pattern in Relevant Tumor Types
A nuclear MCM2 immunostaining in a fraction of tumor cells is always seen in cancerous tissues.
The TCGA findings on MCM2 RNA expression in different tumor categories have been summarized in the Human Protein Atlas.
Compatibility of Antibodies
No data available at the moment
Protocol Recommendations
IHC users have different preferences on how the stains should look like. Some prefer high staining intensity of the target stain and even accept some background. Others favor absolute specificity and lighter target stains. Factors that invariably lead to more intense staining include higher concentration of the antibody and visualization tools, longer incubation time, higher temperature during incubation, higher temperature and longer duration of the heat induced epitope retrieval (slide pretreatment). The impact of the pH during slide pretreatment has variable effects and depends on the antibody and the target protein.
All images and data shown here and in our image galleries are obtained by the manual protocol described below. Other protocols resulting in equivalent staining are described as well.
Manual protocol
Freshly cut sections should be used (less than 10 days between cutting and staining). Heat-induced antigen retrieval for 5 minutes in an autoclave at 121°C in pH 7,8 Target Retrieval Solution buffer. Apply MSVA-502R at a dilution of 1:150 at 37°C for 60 minutes. Visualization of bound antibody by the EnVision Kit (Dako, Agilent) according to the manufacturer’s directions.
Potential Research Applications
- The prognostic role of the percentage of MCM2 positive cells is yet unknown.
- It is unclear whether MCM2 quantification is equally or better suited than the established Ki67-Li for prognosis assessment in tumors with rather low proliferation rate.
Evidence for Antibody Specificity in IHC
In principle, there are two ways how the specificity of antibodies can be documented for immunohistochemistry on formalin fixed tissues. These are: 1. Comparison with a second independent method for target expression measurement across a large number of different tissue types (orthogonal strategy), and 2. Comparison with one or several independent antibodies for the same target and showing that all positive staining results are also seen with other antibodies for the same target (independent antibody strategy).
For proteins such as MCM2 which are expressed in virtually all tissues but restricted to specific cell types and cell compartments, orthogonal validation is not well suited. However, the comparison of MSVA-502R immunostaining data with data from three independent RNA screening studies, including the Human Protein Atlas (HPA) RNA-seq tissue dataset, the FANTOM5 project, and the Genotype-Tissue Expression (GTEx) project, which are all summarized in the Human Protein Atlas (Tissue expression MCM2) supported the specificity of a weak MCM2 staining observed by MSVA-502R in virtually all cells of few tissue types with little proliferative activity such as heart, skeletal, and smooth muscle cells or ovarian stroma cells.
Comparison of antibodies: A specific staining of the MCM2 antibody MSVA-502R is supported by an identical staining pattern – often restricted to proliferating cell types – seen by employing an idependent other commercially available MCM2 antibody (termed “validation antibody”). Staining with the validation antibody also confirmed MCM2 positivity in all cell types with positivity for MSVA-502R which are not notorious for cell proliferation such as for example skeletal muscle, myometrium, ovarian stroma, pneumocytes of the lung, or adrenocortical cells.
