Encapsulation of purified DNA
Referencing and receiving samples
The platform can receive either biological materials or already purified DNA. Samples are referenced in the LIMS (Laboratory Information Management System) prior to their arrival on the service platform where they are identified with a unique code generated by the LIMS (barcode label). Other referencing options are possible, such as labeling by the customer before sending samples.
The biological sample transport procedure and the storage temperature upon reception are defined with the customer, in accordance with the biosafety and biosecurity rules (see the service regulations, available on request).
DNA extraction and purification
The biological materials are extracted according to a method agreed with the client, automated or manual depending on the case. For more details on extractions offers and biological materials supported, see extractions.
DNA quality control
All DNA samples extracted by the platform undergo a quality control to at least know the amount of extracted DNA. For purified DNA sent by the customer this service is optional and flexible.
In routine, the quantity and the quality of each DNA sample are determined by three measurements, in an automated way and in interface with the LIMS:
- Measurement of absorbance by UV spectrophotometry between 220 nm and 320 nm (spectrum). determination of OD ratios A260 / A280, A260 / A230
- Measurement of the fluorescence emission in the presence of a fluorophore specific for double-stranded DNA. This DNA amount measurement is used to calculate the aliquot volumes.
- Electrophoretic migration on non-denaturing agarose gel.
The combination of these analyzes makes it possible to know if the DNA is in sufficient quantity to satisfy the demand, if it is pure enough and of high molecular weight. The volumes to be aliquoted per capsule are calculated by default as a function of the concentration obtained by fluorimetric measurement specific for double-stranded DNA.
This fully automated operation makes it possible to distribute each DNA sample according to the DNA amount or volume per capsule and / or the number of minicapsules requested by the client.
During this operation, the barcode of each DNA sample is associated with Datamatrix codes of the corresponding minicapsules and the information is automatically recorded in the LIMS.
Desiccation of DNA
During this step, the samples undergo a primary vacuum dehydration in an evapo-concentrator where the various drying parameters (pressure drop, chamber temperature) are controlled.
After the primary desiccation step, the DNA cases racks and the caps are introduced into an environment ensuring a controlled (anoxic, anhydrous) and inert (argon, helium) atmosphere.
Under this atmosphere, protected from deterioration factors, the case and the cap of each minicapsule are assembled and sealed by pulsed laser YAG welding for a rigorous seal without temperature rise.
Each minicapsule undergoes, after welding, a systematic tightness check performed by a leak detector (helium detection by mass spectrometry) to ensure a tight seal. In case of leakage, the sample is re-encapsulated.
Delivery of minicapsules
The minicapsules are delivered on their storage racks to the address specified by the customer or stored, on customer behalf, on the platform. Matching data between customer IDs and minicapsule 2D codes (and quality control data where applicable) are also exported from the LIMS database and provided upon delivery.