Technical library - RESOURCES

The majority of PromoCell cell pellets (C-14**) are prepared 1 passage after thawing the cryopreserved cells. Examples: HUVEC and HUAEC correspond to P1 after thawing; therefore the pellets are frozen in P2. SMC or keratinocytes or epithelial cells correspond to P2 after thawing; therefore the pellets are frozen in P3. In contrast, our blood cells are cryopreserved directly after cell isolation. These pellets are prepared after thawing the cryovials with no further cultivation step.

Most primary cells detach within 5-10 min at 37°C. Inactivation isn't required but we recommend to centrifuge the cell suspension to remove accutase and EDTA before replating the cells.

PromoCell Preadipocytes are isolated from subcutaneous or visceral fat. Subcutaneous fat is found just underneath the skin and it is not related to the obesity-linked diseases. Its accumulation represents the normal physiological buffer for excess energy intake. When the storage capacity of subcutaneous fat is exceeded or the generation of new adipocytes is impaired, visceral fat starts to accumulate. It is located in the abdomen and around internal organs (e.g. kidney, heart, or bladder) and it is linked to hypertension, diabetes, and cardiovascular disease. Adipocytes from subcutaneous and visceral fat differ in several functions, like their response to insulin and other hormones or their lipolytic activity. It highly depends on the scientific problem being addressed, which of the two cell types are best suited for your experiments.

At PromoCell we guarantee for our primary human cells ≥ 500,000 viable cells after thawing. For this, we dispense > 500,000 cells per cryovial before cryopreservation as there will always be a certain percentage of dead cells after freeze/thaw. In order to know the number of cells that survived the procedure, we defrost a representative number of vials per lot during QC, determine the cell viability using an electronic counting device and then calculate the number of viable cells that can be recovered after thawing. Both numbers - the calculated number of viable cells and the viability - can be found on the lot-specific Certificate of Analysis (CoA) that can be downloaded from our website. Example: When the CoA indicates 600,000 viable cells and a viability of 80%, this means that the vial actually contains 750,000 cells (viable + dead), 80% thereof (600,000) were viable after thawing in our QC. We do not indicate the total number of cells per vial but just the number of expected viable cells which can be recovered when the recommended thawing protocol is used. You don't have to calculate any viabilities by yourself. When the recommended plating density for your cell type is 5,000 - 10,000 cells/cm², then the 600,000 viable cells can be plated e.g. in a T75 (corresponding to 8,000 cells/cm²) or in a T75 + a T25 (corresponding to 6,000 cells/cm²).

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 our Cryo-SFM Plus (C-29920). It is also recommended to freeze the cells at an early passage.

The DMSO concentration in our Cryo-SFM is 10%.

Note: The sale of Cryo-SFM was discontinued at the end of 2024. Cryo-SFM was replaced by Cryo-SFM Plus.

Baculovirus is generally used in conjunction with insect cells (Sf-9, Sf-21) to produce recombinant proteins (cytokines, growth factors).

None of our Specialized Media (Media for Primary Human Cells; Blood and Stem Cell Media, Cancer Cell Media) contain recombinant proteins produced in insect cells. This also applies to our Cryo-SFM Plus Freezing Medium.

PromoCell cell pellets (C-14**) can be stored indefinitely at -20°C and are stable for up to 1 month at 4°C and up to one week at room temperature. Please note: The samples do not freeze at -20°C.

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).

Our Human Mesenchymal Stem Cells and Human Pericytes are cryopreserved at the end of secondary culture (P1). After thawing, they are in P2.

Usually 90-100% of the hMSC show a neuronal morphology after differentiation with our Mesenchymal Stem Cell Neurogenic Differentiation Medium (C-28015). 60-80% of them are positive for nissl bodies after a nissl stain.

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.