Technical library

The Chondrocyte Growth Medium SupplementMix consists of Fetal Calf Serum (final concentration 10 % v/v) which has specifically been tested for the culture of primary chondrocytes. FCS contains a variety of different growth factors, which are however, not analyzed in more detail. There are no further growth factors added to the SupplementMix.

The optimal calcium concentration for both proliferation and differentiation of keratinocytes depends on the species and also on the media formulation. To keep primary human keratinocytes in the proliferative status, concentrations between 0.03 and 0.15 mM (PromoCell Keratinocyte Growth Medium 2: 0.06 mM) are generally used. Increasing the calcium above 1 mM will induce terminal differentiation and lead to the loss of proliferative activity.

No, we don't perform CD90 immunomagnetic separation with our pericytes. We can however exclude fibroblast contamination as follows: 1) The presence of fibroblasts in our pericyte cultures would be detectable shortly after cell isolation, as pericytes need up to 2 weeks before they start proliferating. Fibroblasts on the other hand would proliferate immediately and overgrow the culture. 2) Characterization of the isolated pericytes during QC includes flow cytometry of CD146. Pericytes express CD146 whereas placental fibroblasts don't.

CD146 (also known as MUC18) is a surface marker that is expressed on pericytes, but it can also be found on mesenchymal stem cells (MSCs) and endothelial cells from large vessels. Importantly, microvascular endothelial cells do not express CD146.
 
Marker combination for pericyte identification
To reliably distinguish pericytes from other cell types, CD146 is used in combination with CD34:

• Pericytes: CD146⁺ / CD34⁻
• Endothelial and hematopoietic cells: CD34⁺

The absence of CD34 expression ensures that the CD146‑positive cells are not of endothelial or hematopoietic origin, allowing a clear identification of pericytes by FACS analysis.
 
Additional pericyte markers
Other markers that have been described for pericytes in the literature include NG2, CD90, α‑smooth muscle actin (α‑SMA), PDGFR‑β.
Please note: These markers are not part of PromoCell's routine Quality Control (QC) testing for pericytes and are therefore not included in the lot-specific Certificate of Analysis (CoA).
 

PromoCell Human Renal Cortical Epithelial Cells (HRCEpC, C‑12660) are isolated from the cortex of the human kidney. The renal cortex is the outer region of the kidney and contains:

• the renal corpuscles,
• the proximal convoluted tubules,
• the distal convoluted tubules, and
• the cortical collecting ducts.

Accordingly, HRCEpC represent a mixed population of epithelial cells originating from cortical nephron segments, including both proximal and distal tubules.

Our HPF (C-12360) are isolated from peripheral lung tissue.

Recommended procedure: - Thaw the vial according to our protocol - Seed one part of the cells (5,000 cells/cm²) directly into multiwell plates for subsequent differentiation induction; grow in Preadipocyte Growth Medium until they reach 100% confluency, then induce differentiation according to the recommended protocol - Seed the other part (5,000 cells/cm²) into a TC dish and expand them in Preadipocyte Growth Medium; trypsinize at subconfluence; if necessary divide the cell suspension again into two parts and use one part for differentiation tests (see above), the other part to continue the culture of undifferentiated HWP. - Differentiation capacity may decline after 1-2 passages in vitro, therefore best perform your differentiation tests at early passages. HWP at higher passages can still be used for studies that require undifferentiated HWP (e.g. proliferation assays).

The basic information we receive from the surgeons about the tissue donors usually includes age, gender, and ethnicity.

• For many of our donors of subcutaneous preadipocytes, we also have information on BMI, hair color, skin pigmentation, and, in some cases, smoking habits or known diseases (e.g. Diabetes). Most of our subcutaneous HWP donors are between ∼20-65 years old.
• The visceral HWP donors are mostly between ∼20-85 years old. For many cell lots we know the BMI, in some cases also the hair color, skin pigmentation, smoking habits, and/or known diseases (e.g. Diabetes or COPD).

If you are looking for particular specifications, please contact our Scientific Support, so that we can offer you appropriate HWP lots.

Further Information

PromoCell's disease cell models

We guarantee 15 population doublings for our NHEM. In terms of passages this corresponds to approx. 6-8 subcultivations.

We can however not guarantee that the activity of all melanocyte genes remains unchanged during this time. Primary cells do gradually change their phenotype in vitro. Therefore, it is recommended to use the cells for the important experiments at low passages.

Mature chondrocytes from articular cartilage are postmitotic producers of extracellular matrix components like collagen types II, IX, and XI and proteoglycans. Upon release from the tissue of origin and seeding in monolayer culture, cells re-enter the cell cycle and proliferate. After a period of approx. 1-3 weeks, they will gradually start dedifferentiation and will adopt a fibroblastic phenotype. Dedifferentiation can be detected by decreased collagen type II or increased collagen type I expression, as well as by the appearance of the fibroblast marker Thy-1/CD90. Re-differentiation can be induced by changing from conventional monolayer culture to a 3-D culture system.