What is the reason for heat-inactivation prior to usage?
Heat-inactivation (heating to 56°C for 45 min) inactivates proteases of the complement system. This could be important for cells which are difficult to culture, or cells which will be used to prepare or assay viruses, used in cytotoxicity assays or other systems where complement may have an unwanted influence. On the other hand, heat inactivation may deplete serum growth factors.
Which sera are routinely used at the DSMZ as growth supplements?
The DSMZ cell lines were all propagated in FBS/FCS (fetal bovine/calf serum) or HS (horse serum). With one exception (PB-1, ACC-no. 241) we use only heat-inactivated serum.
Which cell culture media are used at the DSMZ?
The media we use are currently sourced from Invitrogen. This, however, should not be taken as an endorsement. All media contain L-glutamine.
Why are passage numbers omitted from the cell line data sheets?
We believe that passage numbers are unreliable criteria for ageing cell lines. Given that "passage" is defined as the trypsination of a culture and its subsequent re-seeding, passage-numbering arbitrarily depends on the split ratio used by the individual cell culturist. Thus, if operator A splits 1:2, and B 1:4, they will end up with two different passage numbers ("B" half of "A"), even though both cell cultures will have been growing for the same time period.
How should I send samples for mycoplasma testing?
Seal the reaction tubes with Parafilm and wrap carefully. Send the samples unchilled by conventional mail or courier chosen to ensure same-week delivery.
If you prefer to send frozen cultures, add sufficient dry ice (about 4 kg) and send by courier for same-week delivery.
Address package to:
Dr. Cord Uphoff
DSMZ - Department of Human and Animal Cell Lines
Mascheroder Weg 1b
D-38120 Braunschweig, Germany
How should I prepare and send samples for virus detection?
Human pathogenic viruses exhibit greater genomic diversity than bacterial contaminants. The human pathogenic viruses consist of DNA and RNA viruses and have different infective characteristics. Thus, different sample materials and procedures are used for the analyses. The following list shows the sample material matching the different virus types:
HIV-1, HIV-2, HTLV-I/-II, EBV: genomic DNA
HCV, EBV: total RNA or cDNA
HBV: DNA from cell culture supernatant
When frozen cultures are sent we will thaw and culture the cells for several days to collect the samples. This additional labour incurs a surcharge. Cryopreserved cultures should be sent on dry ice by courier.
If you send a growing culture, we will immediately collect the samples depending on the assays to be performed. This is the easiest and least expensive way to perform the assays. The culture vessels should be filled with medium and may be sent by conventional mail or courier despatched no later than on Wednesday's.
DNA and/or RNA/cDNA may also be sent. This material should be sent refrigerated or as precipitate at room temperature. Supernatants for HBV detection maybe sent at room temperature.