DNA Extraction

For DNA samples submitted, Customer is required to ensure the Quality Control (QC) data at the time of sample submission meets the minimum requirements concerning the total amount, concentration, and quality of the DNA submitted. For microbial culture or direct environmental samples submitted, Customer is obligated to ensure that the sample submitted is non-pathogenic to humans and does not contain any substance that may pose a health risk to the personnel working with the samples in our laboratory.

DNA sample

• Total quantity ≥ 1.0 µg (short-insert library) or ≥ 5 µg (PCR-free library);

• Concentration ≥ 20 ng/µL;

• Purity: A260/280=1.8-2.0.

Notes:

(1)  The final concentration of each sample will be measured using QUBIT or an equivalent fluorometer after the samples are received. If the samples do not pass QC, We will notify the Customer, and Customer shall either notify us to cancel the failed samples or re-send the samples concerned within ten workdays. Customer can request that the “QC-failed samples” be sequenced, in which case we will prepare the library and sequence the “QC-failed samples” without bearing any responsibility for the data quality. Customer should notify whether plasmid, chondriosome, chloroplast, and other non-bacterial-origin DNA exist in the samples submitted. Customer should notice that, If the DNA originates from a mixture of multiple microbial species, the quality of final assembly and genome annotation will be compromised significantly, and we will not attempt to separate all assemblies into individual species by any means.

(2)  An aliquot of DNA sample may be stored temporarily in case of a failed library preparation. All DNA samples will be discarded within 3 months after the project is completed.

Microbial pure culture sample

Agar plates: 

colonies should be easily visible and cover > 20% of the surface area on a standard-size petri dish (⌀ 90mm); the agar should not dry out and maintain a good texture for easy collection of cells with a standard sterile loop used in microbiology laboratories.

Pellets: 

Bacterial pellets should be placed in a 1.5 mL or 2 mL centrifuge tube. The size of the pellet shall not be less than that generated by centrifuging 2 mL of E. coli cultures grown in LB overnight at 37 °C, typically covering a round area of ⌀3-5 mm.

Notes:

Customer should pay close attention to contamination on agar plates or in bacterial pellets. Customer must ensure each sample submitted is a single pure culture without being mixed with other species. In any case, we will continue the workflow and sequence the genomic DNA extracted from the samples submitted. We will not accept the complaint on the culture’s purity issue filed by Customer based on the genome sequence data generated in this project.

Environmental sample

The direct submission of soil, lake water, filters, swabs, plant or animal materials, any items or objects colonized by microbes, and other types of environmental samples that contain microbial inhabitants for genomic investigation at our laboratory is subject to individual agreement by email or in other written form between Customer and us concerning the sample type, quantity, and quality before the commence of this agreement.