Have a question about one of our products? Check out our technical library for recently asked questions from other scientists around the world.
Technical Library
Recent Entries in Technical Library
290 Entries on 6 Pages
-
The components of my DetachKit show different colors. Is this normal or does it affect their quality?
The components of the PromoCell DetachKit may arrive on occasion with a non-uniform color appearance. This phenomenon is known by PromoCell’s Quality Assurance. It is reversible and does not influence the quality of the product.
Related Links and Documents
-
I am performing MSC chondrogenic, adipogenic, and osteogenic differentiation and am staining the cells. The protocol says to use Saccomanno Fixation Solution. Is there an alternative method to fix the cells because I don’t have Saccomanno Fixation Solution?
Yes, you can use 4.5% neutral buffered formalin. Paraformaldehyde should work as well.
Related Links and Documents
-
Why is PBS added in the last step of the Alizarin Red staining protocol (“Osteogenic differentiation and analysis of MSC”)? Should the PBS be aspirated before analysis?
The PBS buffering enhances the Alizarin Red staining (precipitation of the dye) and makes it more intense.
Leave the PBS on the cells after staining/washing and analyze the sample immediately, as the dye may bleed upon prolonged storage without embedding.Related Links and Documents
-
What is the shelf life of primary cells cryopreserved in liquid nitrogen?
PromoCell cells are frozen down in the gas phase of liquid nitrogen (computer-controlled freezing machine) and then stored in the liquid phase of LN2.
The cryopreservation in LN2 is an acknowledged method for long-term storage of primary cells and stem cells. When stored in liquid nitrogen, the cells can be maintained for a period of > 10 years without affecting viability.
For example, Kumar et al. showed that adipose-derived stem cells stored in LN2 for about 12 years still retained their regenerative potential, stem cell property, viability as well as differentiation ability.
Related Links and Documents
-
Do all PromoCell HUF come from the myometrium or does the uterine location vary by lot?
All our Human Uterine Fibroblasts (HUF) are prepared from the myometrium.
Related Links and Documents
-
Which DC medium does PromoCell recommend for freshly isolated MNC or monocytes, which one for cryopreserved monocytes?
The PromoCell DC Generation Media have been developed for the easy and efficient generation of immature as well as fully mature myeloid dendritic cells from peripheral blood monocytes.
For freshly isolated mononuclear cells (MNC) and monocytes we recommend our DC Generation Medium XF (C-28052), for cryopreserved monocytes our DC Generation Medium (C-28050). When using DC Generation Medium (C-28050) with fresh MNC, the Monocyte Attachment Medium (C-28051) is needed in a first step for efficient adherence of the monocyte fraction.
Please see Instruction Manual, Application Note and the graph below for further details.Related Links and Documents
-
What are the key points relating to proliferation, differentiation and culturing of HWP?
PromoCell’s Normal Human White Preadipocytes (HWP) are isolated from adult subcutaneous or visceral adipose tissue from different locations. The cells are frozen in our serum-free freezing medium (Cryo-SFM) at the end of passage 1 (= secondary culture). A randomly selected vial is then used for quality control, which includes determination of growth characteristics, control of morphology, and tests for differentiation capacity into mature adipocytes.
The recommended seeding density of preadipocytes after thawing/trypsinization is 5,000 cells/cm2; cells should be trypsinized before reaching 90% confluence. Population doubling times are usually between 20-50 hrs (10 population doublings guaranteed). Using a 1:4 split ratio, you can perform ∼4-5 passages with the cells.
Preadipocyte Growth Medium (C-27417) is used to propagate the cells. To induce differentiation of preadipocytes into adipocytes, cells are grown in PromoCell’s Preadipocyte Growth Medium until they reach 100% confluency. Cells are then cultured in Preadipocyte Differentiation Medium (C-27437) for 72 h, followed by 10-14 days in Adipocyte Nutrition Medium (C-27439). During this time the cells start to accumulate fat droplets which can be visualized under the microscope.
We recommend performing differentiation experiments at population doubling numbers lower than 4-5, in order to reach a high differentiation level of the culture.Related Links and Documents
-
Why is the serum content of PromoCell’s specialized media so low?
FCS is a natural product consisting of many different components like salts, hormones, vitamins, trace elements, proteins, and enzymes. There can be large lot-to-lot variations between different serum batches regarding the concentrations of growth-promoting factors. The higher the serum content in a culture medium, the higher the impact of the variations on the cell culture system. For this reason, PromoCell has developed several serum-reduced and serum-free media where part of the serum has been replaced by more defined factors like cytokines, hormones or vitamins.Media with reduced serum concentrations have the benefit that they produce more standardized culture conditions over a long time span.
-
Does PromoCell determine the percentage of HDLEC in its HDMEC lots?
No, we don’t determine the ratio of HDLEC and HDBEC in our HDMEC lots. From our experience, the percentage of HDLEC is highly lot-dependent and can vary between 5 and 60%.
Related Links and Documents
-
Can I use the Growth Medium instead of TNS to stop the trypsin when splitting the cells?
A concentration > 10% FBS is needed to completely inactivate the trypsin. As most of PromoCell’s growth media are serum-reduced or serum-free, the use of a trypsin inhibitor like TNS is highly recommended.
Related Links and Documents
-
When should I use DetachKit, when DetachKit-2?
Our DetachKit (C-41200) is optimized for primary cells and can be used to trypsinize all Normal Human Cells supplied by PromoCell.
Detach Kit-2 was developed for very gentle detachment and is still used by some investigators to subculture Human Nasal Epithelial Cells (HNEpC).Related Links and Documents
-
Can I detect the differentiation of Mesenchymal Stem Cells by their morphology, without doing any cell staining?
- Adipogenic differentiation can be identified morphologically and without any staining by the formation of intracellular lipid vesicles.
- In contrast, when MSC differentiate into bone cells, there is no significant change in morphology. It is recommended to perform Alkaline Phosphatase staining to detect osteoblastic differentiation or Alizarin Red S staining to show osteoblast mineralization.
- Chondrogenic differentiation is generally performed as spheroids in 3-D cell culture and not in 2-D monolayer culture. Staining with Alcian Blue to visualize the differentiation process is indispensable.
- Neurogenic differentiation can be detected using neuron specific markers (e.g. beta-3 tubulin, NeuN, MAP2) and by their typical neuronal morphology.
For differentiation protocols, please see attached Application Notes.
Related Links and Documents
-
What markers does PromoCell test to characterize their Adult Human Stem and Blood Cells?
All Adult Human Blood and Stem cells are analysed by flow cytometry to express defined markers. MSCs are additionally tested for their capacity to differentiate into the osteogenic, chondrogenic and adipogenic lineages. For more details, please see Certificate of Analysis of the respective cell type (“Phenotypic characterization”).
Related Links and Documents
-
Can the cell pellets be used to establish a growing culture?
No, the PromoCell cell pellets (C-14**) are frozen at -20°C and cannot be revived. Their main application is to analyze RNA or protein. Cryopreserved cells that can be revived are available from the same donors. Please contact our Technical Customer Support if you need matched viable cells.
-
How many passages can I perform with PromoCell Normal Human Cells?
PromoCell does not determine the number of passages but instead we calculate the population doublings (PD) that can be performed with the cells. The term passage only describes the process of detachment and replating and does not take into account different split ratios. The optimal split ratio is calculated from the actual cell yield after trypsinisation and the recommended plating density. In most of our cell types, the split ratio is usually between 1:3 and 1:6. Using 1:4 splits (i.e. increasing the growth surface by factor 4 each time), 15 doublings are achieved after 6-8 passages.
For recommended plating densities, please view the respective Manual, section “Specifications”. -
Can I first expand the osteoblasts and then perform my experiments?
Normal osteoblasts, similar to other non-transformed cell types can be expanded in vitro to a certain extent before they are used for experiments. Nonetheless, HOB are generally used at low passages (up to P4) in most labs.
Related Links and Documents
-
Does the Chondrocyte SupplementMix (C-39635) contain any growth factors?
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.
Related Links and Documents
-
Where does PromoCell source the bronchial tissue for HBEpC preparation? Are the smoking habits of the donors known?
We source the bronchial tissue from forensic medicine and from thoracic surgery. For some lots, the smoking habits of the donors are known.
Please contact our Technical Customer Service before ordering the cells if you need this information.Related Links and Documents
-
Is vWF a great marker for Endothelial Cells?
Secretory granules called Weibel-Palade bodies (WPBs) containing Von Willebrand factor (vWF) are more linked to the formation of a confluent endothelial monolayer. Research shows that vWF expression is dynamic and highly dependent on the cell culture conditions such as confluence and passage number.
Therefore, having vWF as a quality control marker for each lot of ECs is not really necessary.Related Links and Documents
-
I would like to differentiate hMSC into bone cells and further maintain the cells in culture after differentiation. Which medium should I use?
Osteogenic differentiation of hMSCs with PromoCell MSC Osteogenic Differentiation Medium takes ∼12-14 days (please view the respective Application Note for a detailed protocol). Use fibronectin-coated plates and change the medium every third day.
The bone cells tend to detach from the plastic after approximately 2 weeks, when differentiation is complete. Therefore, the tests should be performed promptly and the cells should be maintained in MSC Osteogenic Differentiation Medium until then.
Related Links and Documents
-
Are your NHEK from the epidermis of the juvenile foreskin mucosal or cutaneous keratinocytes or a mixed population?
PromoCell’s Normal Human Epidermal Keratinocytes (NHEK) from juvenile donors are isolated from both the epidermis of the outer and mucosal (i.e. inner) layers of the foreskin. Thus, each vial contains a mixture of mucosal and cutaneous keratinocytes.
Related Links and Documents
-
I would like to know if, in addition to HBEpC, the other airway epithelial cells are also compatible with PromoCell ALI medium.
- For our HNEpC and HTEpC, please refer to the instructions in the AppNote describing the differentiation of these cell types using our ALI medium.
- We do not provide instructions for HSAEpC because our medium is not suitable for differentiation of this cell type at the air-liquid interface.
- For our HBEpC we have special ALI prescreened lots in stock that were successfully tested for barrier function in our QC. Please contact our technical customer support for more information.
Related Links and Documents
-
What could be the reason for a lower yield when using M2 Macrophage Generation Medium compared to M1 Macrophage Generation Medium for a culture started with the same monocytes?
For the M2 Macrophage Generation Medium, it is extremely important that the shelf life of 2 weeks (after addition of the cytokines) is not exceeded; the yield will quickly decrease thereafter. It is best to use the M2 medium as fresh as possible to avoid discrepancies between M1 and M2 yield.
Related Links and Documents
-
Can PromoCell recommend a medium to co-culture endothelial cells and fibroblasts?
Some of our customers have successfully used PromoCell Endothelial Cell Growth Medium MV2 (C-22022) when co-culturing Human Coronary Artery Endothelial Cells (HCAEC; C-12221) and Normal Human Dermal Fibroblasts (NHDF; C-12300).
Related Links and Documents
-
What are the advantages of using PromoCell DC Generation Medium XF for dendritic cell generation?
Our DC Generation Medium XF (C-28052) has a xeno-free formulation. It provides a complete media system (ready-to-use, all cytokines included) and shows efficient and reproducible in vitro maturation of moDCs from freshly isolated peripheral blood monocytes.
Related Links and Documents
-
How does PromoCell ensure that there is no fibroblast contamination in the pericytes? Are the fibroblasts removed by separation with anti-CD90 labeled magnetic beads?
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.Related Links and Documents
-
My cells didn’t detach during subculture. What could be the reason?
Please find attached a trouble shooting guide to identify possible reasons for poor detachment during subculture.
Related Links and Documents
-
Why is the growth rate of PromoCell’s HDMEC significantly reduced when I remove hydrocortisone from the Endothelial Cell Growth Medium MV Kit (C-22120)?
Epidermal Growth Factor (EGF) and hydrocortisone have been reported to have a synergistic effect on the growth of microvascular endothelial cells. Accordingly, if you remove the hydrocortisone, the proliferation of HDMEC is clearly affected.
Related Links and Documents
-
Should I warm the trypsin prior to use?
We recommend to use the trypsin as well as the other detach solutions at room temperature to avoid overtrypsinization and irreversible cellular damage.
Related Links and Documents
-
What is the difference between DetachKit (C-41200) and DetachKit-2 (C-41202)?
Both Kits contain HepesBSS, trypsin/EDTA, and Trypsin Neutralizing Solution (TNS). In DetachKit (C-41200), the concentration of trypsin/EDTA is 0.04% / 0.03%. In DetachKit-2 (C-41202), it is reduced to 0.025% trypsin / 0.01% EDTA. HepesBSS and TNS concentrations are identical in both Kits.
Related Links and Documents
-
How does PromoCell characterize their MSC-AT (C-12977)?
Our hMSC-AT are characterized by their differentiation potential into chondrocytes, fat cells, and bone cells. In addition, we determine the presence of CD73, CD90 and CD105 expression as well as the absence of CD14, CD19, CD34, CD45 & HLA-DR expression by flow cytometry as proposed by the International Society for Cellular Therapy.
Related Links and Documents
-
Do I have to use coated tissue culture vessels for culturing PromoCell Normal Human Cells?
It is not necessary to use coated flasks for (most of) our Normal Human Cells but it can be done. As coating with extracellular matrix proteins can affect cellular metabolism, it is recommended to use the same coating material for a complete set of experiments.
Cells that need to be grown on coated dishes:- Mesenchymal Stem Cells (C-12974/C-12971/C-12977) need Fibronectin-coating when grown in PromoCell MSC Growth Medium XF (C-28019) and when differentiated in MSC Neurogenic (C-28015), Adipogenic (C-28016), or Osteogenic (C-28013) Differentiation Media.
- Human monocyte-derived macrophages (C-12914/C-12916/C-12915/C-12917) must be seeded into Fibronectin-coated culture vessels in combination with PromoCell’s M1- and M2-Generation Media XF (C-28055, C-28056).
- For efficient induction of osteoblast mineralization with PromoCell’s Osteoblast Mineralization Medium (C-27020), the TC plates should be pre-coated with collagen type I.
Related Links and Documents
-
At what passage do PromoCell test the cell type-specific markers?
Cell type-specific markers are usually determined one passage after thawing.
Example: After thawing, HUVEC are in P1. Markers (CD31 expression, Dil-Ac-LDL uptake) are tested in P2.
Please note: Cells that are frozen directly after isolation (blood cells) are tested directly after thawing with no further culturing step. -
What is the definition of “adult stem cells”?
“Adult stem cells” are stem cells isolated from postnatal tissues that have retained the capacity for cell renewal as well as for differentiation into multiple lineages (multipotency).
Related Links and Documents
-
Does the Osteoblast Growth Medium support osteoblast proliferation or differentiation? Does the medium contain any recombinant growth factors?
Our Osteoblast Growth Medium (C-27001) consists of the Basal Medium supplemented with 10% (v/v) FCS, but with no recombinant growth factors. The medium primarily supports the proliferative capacity of normal human osteoblasts. It does not contain osteogenic factors (like dexamethasone and beta-glycerophosphate) that promote differentiation as many users test their own chemical compounds (growth factors, hormones), or examine the effects of physical strain or sheer stress on the differentiated functions. The Osteoblast Growth Medium is well-suited as the basis for these applications and can be supplemented with further growth factors if necessary. To specifically induce mineralization, PromoCell supply Osteoblast Mineralization Medium (C-27020).
Related Links and Documents
-
Is it feasible to store the melanocytes for a second time in liquid nitrogen after subculture, similar to cell lines?
Upon arrival, you can either defrost the cells immediately and seed them in a TC vessel or store the vial in liquid nitrogen until needed.
It is possible to re-freeze normal human cells but PromoCell does not recommend it, because each freezing cycle leads to a loss in proliferation potential. If you want to freeze them, please use Cryo-SFM (C-29910) which is a serum-free freezing medium that prevents the possibility that any serum is introduced into your serum-free cell culture system. It is also recommended to freeze the cells at an early passage.Related Links and Documents
-
What is the exact localization of PromoCell’s HNEpC (C-12620)?
Our Nasal Epithelial Cells are isolated from nasal septum or adenoids.
Related Links and Documents
-
Are endothelial cells α-SMA-negative under all circumstances?
Scientific findings from different groups, as well as our own results indicate that the presence or absence of α-SMA is not a valid indicator for the composition of a given cell population. Research findings and our inhouse data suggest that endothelial cells are not α-SMA-negative under all circumstances. α-SMA negativity is not an intrinsic property of endothelial cells but can vary depending on extrinsic influences.
Lot-specific values for α-SMA in our Certificates of Analysis (CoAs) are therefore not considered meaningful.
Related Links and Documents
-
Which human AB serum does PromoCell recommend to generate M0 macrophages?
We recommend to use Human Serum AB „off-the-clot”.
Related Links and Documents
-
Can your Macrophage Detachment Solution also be used for bone marrow-derived macrophages from mice?
Yes, there is a reference (Campuzano et al.; J Immunol. 2020 Jun 15;204(12):3296) where bone marrow-derived macrophages from mouse were detached using our Macrophage Detachment Solution (40 minutes at 4°C).
Related Links and Documents
-
Can I use frozen PBMCs instead of CD14+ monocytes to generate dendritic cells with PromoCell DC Generation Medium?
PBMCs (= peripheral blood mononuclear cells) consist mainly of lymphocytes and monocytes. Cryopreservation causes the CD14+ monocytes to significantly lose their ability to attach to TC plastic. Therefore, the use of frozen PBMCs as starting material for DC generation is not possible because the purification step with Monocyte Attachment Medium will not work.
You can either start with cryopreserved CD14+ monocytes (C-12909) or use freshly isolated mononuclear cells or fresh CD14+ monocytes.
Please refer to the Product Manual of C-28050 or our Application Note [Generation of monocyte-derived Dendritic Cells] for the appropriate protocol.Related Links and Documents
-
After detaching the macrophages for flow cytometric analysis, I noticed that the washing and centrifugation steps take a long time. Can I shorten the spin time to 10 minutes at 350 x g?
Spinning the cells for 15 min at 350 x g has been proven and tested by PromoCell Research & Development. The QC department uses these settings during testing. Any lower centrifugation value (g-force and/or time) will lead to significant cell loss by means of non-sedimented, but intact, macrophages.
Related Links and Documents
-
We are culturing human coronary artery smooth muscle cells (HCASMC) from your company. Are these cells obtained from large arteries like LAD or left Circumflex or from small branches of LAD etc. ?
Our HCASMC (C-12221) are isolated from the large arteries, i.e. from
- Right coronary artery
- Left main coronary artery
- Circumflex coronary artery and
- Left anterior descending coronary artery.
Related Links and Documents
-
How long does it take to differentiate monocytes into mature DCs using PromoCell DC Generation Medium/DC Generation Medium XF?
It takes 7-8 days to generate fully mature myeloid dendritic cells.
Related Links and Documents
-
What is the exact localization of PromoCell’s Human Pericytes? How many doublings can they perform in culture?
Our hPC-PL (C-12980) are isolated from microvessels of the human placenta, from the chorionic villi.
The number of populations doublings is not determined for each individual cell lot, but in our experience, they can be grown for at least 15 population doublings.Related Links and Documents
-
My Normal Human Cells didn’t attach after thawing. What could be the reason?
Poor attachment after thawing can be a result of inappropriate freezing, storing or thawing the cells as well as from inadequate culture conditions (medium, incubator). The attached trouble shooting guide should help you to identify the possible reasons.
Related Links and Documents
-
Is it possible to split differentiated adipocytes in order to perform more experiments?
Generally, you can split differentiated adipocytes. But these cells lose their ability to proliferate after differentiation and you can’t expand the culture any more. Therefore it is recommended to plate the cells into the needed vessels (e.g. multiwell plates) prior to induction of differentiation so that trypsinization isn’t necessary.
Related Links and Documents
-
What is the concentration of the trypsin inhibitor in TNS?
Our TNS solution contains 0.05% (w/v) trypsin inhibitor from soy bean in HepesBSS/0.1% BSA.
Related Links and Documents
-
What is the shelf life of the PromoCell DetachKit/DetachKit-2?
The three components of DetachKit and DetachKit-2 (HepesBSS, Trypsin/EDTA, TNS) are stable for 1 year from the date of manufacture when stored at -20°C. Once thawed for usage, they should be stored at 4-8°C and can be used for 6 weeks. Please avoid repeated freeze/thaw cycles.
Related Links and Documents
-
I would like to know the number of population doublings for PromoCell mononuclear cells (C-12907/C-12901) when grown in Mononuclear Cell Medium (C-28030).
Mononuclear cells are mostly used in immunology, infection biology, hematology and cancer research to study subpopulations of blood cells.
Our Mononuclear Cell Medium (C-28030) is intended for short-term maintenance (up to 48 hrs) of the thawed hMNC before you proceed with your experiments. The number of PDs will depend on the subsequent cell culture conditions and is not determined by PromoCell.
Please note: Depending on the conditions, the ratio of the subpopulations will gradually change, as the different blood cell types behave in different manners. Researchers normally start soon after thawing to either select the cell type of their interest (e.g. hematopoietic cells, endothelial progenitor cells) or perform experiments with all populations of hMNCs (e.g. to study effects on toxicity, viability or metabolism).Related Links and Documents
Choose your Region
Please choose your region for an optimized website experience. So we can provide you with the most useful information for your country.
- North America
- Europe
- Asia