Technical library

The practice of heat inactivation was originally developed when only serum from adult animals was available. Adult serum contains high serum complement which may destroy cells under certain conditions.

Heating serum (30 min, 56°C) is intended to inactivate the complement.

Today, serum is often heat-inactivated without any evidence of beneficial effect. When using FCS (fetal calf serum), heat inactivation is not necessary for most cell lines or cell types.

PromoCell does not use heat-inactivated serum for the production of its growth media.

After addition of the SupplementMix or SupplementPack to our basal medium, you obtain the complete growth medium. No further supplementation with serum or growth factors is required. Please note: Our media do not contain antibiotics. If you wish to use antibiotics you can add penicillin/streptomycin or gentamicin/amphotericin B at standard concentrations. Addition of antibiotics can however reduce the doubling time of the cells up to 30-40%.

Yes, primary mouse keratinocytes grow well in this media when you reduce the CaCl₂ concentration to 0.025 mM - 0.05 mM CaCl₂ (optimal Ca concentration for primary human keratinocytes is 0.06 mM).

Usually, we do not recommend specific plasticware but we have found that with PromoCell’s Dendritic Cell and Macrophage Generation Media, choice of plasticware can have a lot of an influence. For our M1-/M2 Macrophage Generation Media XF we recommend the Nunc plasticware with Nunclon surface - as not only will the detachment efficiency vary (up to 20%), but also the efficiency of the differentiation process itself may be altered.

Our customers have successfully used TC flasks and dishes from all the leading cell culture plastic suppliers to grow PromoCell's primary human cells. We do not have any knowledge whether the dishes from local TC plastic suppliers work in the same way. We recommend to first test whether these brands provide the same good performance as the plastic of the leading manufacturers.

Samples in RNAlater will NOT freeze at -20°C, they are liquid at 4°C and -20°C. The samples can be stored at 4°C for up to 1 month and are stable at room temperature for up to one week. At -20°C, they can be stored indefinitely.

Yes, it is possible to transfect our normal human cells. In general, primary and normal cells are much harder to transfect than immortalized cell lines. Apart from the cell type, successful transfection also depends on the culture's age and density at transfection, the vector used, the purity of the nucleic acids, the composition of the transfection medium, and the experimental conditions.

Precoating of culture vessels with ECM proteins does not have adverse effects on the cells but has been reported to influence the cellular expression pattern. It is therefore recommended to use the same culture conditions, e.g. fibronectin-, collagen-, or gelatin-coating for a whole set of experiments to be able to compare the results.

PromoCell generally culture their HOB on uncoated tissue culture dishes. It is possible however to grow them on collagen type I- or fibronectin-coated dishes as well. Please note: The type of extracellular matrix used may influence the expression of certain genes (e.g. integrins) and thereby affect cellular metabolism. Therefore, we recommend to always use the same type of coating matrix for a whole set of experiments.

If you are growing our NHEK in PromoCell Keratinocyte Growth Medium 2 (C-20011) or Growth Medium 3 (C-20021), you don't need any feeder cells. The cells will grow as a monolayer in conventional tissue culture flasks.