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Hot Products
- In-Stock Tumor Cell Lines
- Human Orbital Fibroblasts
- Human Microglia
- Human Pulmonary Alveolar Epithelial Cells
- Human Colonic Fibroblasts
- Human Type II Alveolar Epithelial Cells
- Human Valvular Interstitial Cells
- Human Thyroid Epithelial Cells
- C57BL/6 Mouse Dermal Fibroblasts
- Human Alveolar Macrophages
- Human Dermal Fibroblasts, Adult
- Human Lung Fibroblasts, Adult
- Human Retinal Muller Cells
- Human Articular Chondrocytes
- Human Retinal Pigment Epithelial Cells
- Human Pancreatic Islets of Langerhans Cells
- Human Kidney Podocyte Cells
- Human Renal Proximal Tubule Cells
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When preparing culture media, does serum need to be heat-inactivated?
Heat inactivation of serum is used to inactivate complement and may be necessary depending on the experimental purpose. Serum should generally be heat-inactivated in situations such as immunological studies, smooth muscle cell culture, embryonic stem cell differentiation, or any culture processes sensitive to complement. In other cases, heat inactivation is not required, which helps preserve growth factors present in the serum.
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What is the recommended split ratio for tumor cell lines?
A common split ratio is 1:2 to 1:4. For primary cultures (P1), a denser seeding (e.g., 1:2) is recommended to help cells stabilize. Splitting too sparsely can halt proliferation, as tumor cells are highly density-dependent. Over-digestion can damage surface proteins, reducing cell attachment efficiency.
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What is considered a normal survival rate after thawing, and should the medium be changed immediately?
During freezing, cells experience osmotic stress and ice crystal formation, so some cell death is normal. Adherent tumor cells are generally more sensitive to freezing. A post-thaw survival rate of 70–90% is considered normal. Do not change the medium immediately after thawing to avoid detaching newly adherent cells; it is recommended to replace the medium 24 hours later to remove DMSO.
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Is it normal if cells become rounded, bright, or show a large number of floating cells?
A small number of floating cells can be normal. However, the following conditions should be checked if extensive changes occur:
Overconfluence
pH fluctuations
Nutrient depletion
Over-digestion during passaging
Microbial or mycoplasma contamination
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Can tumor cell lines be passaged indefinitely?
Tumor cell lines are immortalized and, in theory, can be continuously passaged. However, prolonged culture may lead to genetic drift. It is therefore recommended to complete critical experiments within 10–20 passages.
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What is the survival rate of tumor cells after thawing?
Freezing and thawing inevitably cause some cell damage, particularly for adherent tumor cells. Generally, a survival rate of 70–90% is considered normal. During the first 24 hours after thawing, avoid frequent handling or agitation of the culture flask to ensure optimal recovery.
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How does freezing and thawing immortalized cells differ from regular cells?
The process is basically the same. However, immortalized cells generally proliferate faster after thawing, and adherent cells usually reattach within 12–24 hours.
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Are immortalized cells equivalent to tumor cells?
Not exactly. Some tumor cells naturally possess immortal characteristics, whereas primary cells that have been immortalized through transfection generally retain a more primitive phenotype and function. They do not exhibit the high proliferation and invasiveness typical of tumor cells.
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Does immortalization affect cell phenotype?
It may, but the extent depends on the immortalization method and the cell type. For example, SV40 Large T or HPV E6/E7 can alter proliferation, cell cycle, or certain signaling pathways. In terminally differentiated cells like neurons, which are initially non-proliferative and morphologically specialized, the cells after transfection and selection may differ significantly from the original primary cells.
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Do immortalized cells exhibit batch-to-batch variations?
Yes, but usually to a lesser extent than primary cells. Factors that can influence variation include:
The immortalization method used (e.g., hTERT vs. SV40T)
Passage number and culture duration
Different donors
For large-scale experiments, it is recommended to purchase multiple vials from the same batch and use them consistently.
