Frequently Asked Questions (FAQs)
What kind of material can be submitted?
We can process and analyze biological material up to biosafety level 3 ** as well as genetically modified organisms up to level 2. Our services are intended for quality control purposes only, not for clinical diagnosis.
How much sample should be submitted?
Most of our assays require a minimum of 600 μl / sample. Some assays like endotoxin testing or a full human virus testing pannel (6 viruses) require 1 and 2 ml of sample, respectively.
Can I submit native material?
It depends on the test selection and your own shipping preferences. Native material usually requires cooled transportation (dry ice or cool packs) and this usually results in higher shipping costs. The inactivation is then carried out in our laboratory during sample preparation (for nucleic acid extraction through the so-called lysis step).
Up to which cell concentration is a NAT measurement possible?
Our extraction and QPCR systems deliver valid results for sample material up to a cell concentration of 1 x 106 cells/ml. If this concentration is exceeded, inhibitions can take place in the qPCR. At lower cell concentrations, the analysis loses sensitivity with regard to the detection of cell-associated microorganisms. If you would like to analyze higher cell concentrations, we have special sample preparation techniques and analytical methods to support you. You are welcome to contact us for more information.
What are other possible causes of inhibitions in NAT analysis?
Excessive cell counts are often the cause of inhibition during analysis. Other causes include a high DNA-background, protein concentration and / or reagents contained in the medium that have an inhibitory effect on Taq polymerase (e.g. DMSO). If such reagents are contained, please let us know, as we may be able to compensate for the inhibitory effects using a complementary extraction method.
What is the benefit / purpose of inactivation over native material?
Proteins are denatured by the inactivation, in particular the DNAases are of high relevance for DNA-based nucleic acid analysis. Samples for RNA-based nucleic acid analysis are not sent inactivated, but natively frozen. RNases are highly thermo-stable and incomplete inactivation would lead to a strong degradation of the RNA.
Should I inactivate my sample before submission and how?
Heat-inactivated samples (95 ° C for 10 minutes) are shipped in a sterile reaction tube to prevent DNA degradation and false negative results. For this type of inactivation, the volume should not exceed 1.0 ml to ensure complete inactivation. For larger sample volumes, the inactivation time must be adjusted. Materials treated in this way are stable for up to 7 days at room temperature. We have performed an extensive stability study, please contact us in case you require more advice on how to proceed.
When is inactivation not useful?
With certain sample matrices or cell concentrations gelation can take place during inactivation. As a rule, gel formation is not compatible with nucleic acid extraction; this should be investigated in a preliminary test in your laboratory. It is important in this experiment to cool the sample after inactivation and only then to examine it for gel formation (e.g. by carefully turning the closed sample container upside down). In the case of non-nucleic acid-based methods, the sample should also not be inactivated if this changes the target molecule.
How do I send my samples?
The samples to be analyzed should be transferred to a sterile reaction tube (preferably 1.5 ml reaction tubes with a safety cap) (‘primary packaging’). Place the primary packaging in a ‘secondary packaging’ (e.g. 50 ml tube, ziplock bag, closed plastik grid box), which is ideally filled with cotton wool or polystyrene flakes to compensate for transport shocks. You send the secondary packaging in a transport box or a padded envelope to our laboratory (the shipping address can be found on the respective ‘Accession Form / order form’ in the customer area: order forms).
Do you have any shipping recommendations?
We recommend shipping with a courier service. Samples sent by post cannot be tracked and must fit in a standard letter slot. Occasionally we also had to find out that some postal samples are lost or delivered delayed if it takes too much effort deliverer. The probability of loss / default was 0.01-0.06% for postal samples in 2019.
How do I create an account when I submit samples for the first time?
It is surprisingly easy: You file your contact data on the respective submission form and send it together with your samples. We create an account and you will receive your results report via Email / Fax in advance and the original via post a couple of days later.
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