Complete Genomics does not concentrate or dilute samples that are outside of the required concentration range, as described in the Sample Submission Instructions. The liquid handling systems used for sample and library preparation have not been validated for concentrations and volumes outside of the required ranges. Because samples cannot be accepted outside of the concentration range, and there can be variability between customer measurements and Complete Genomics measurements, we recommend that the sample have a concentration well within the range required, rather than at the border of the range.

If the DNA is too concentrated, it can be diluted by adding 1x TE, pH 8.0.

If the DNA is too dilute, recommended options to concentrate the sample include the following:

• Amicon® ultra centrifugal filter units from Millipore
• Agencourt Ampure XP beads
• QIAGEN QIAamp DNA Micro Kit (catalog # 56304, Cleanup of Genomic DNA Protocol)
• Ethanol precipitation, using NaAoc and not NaCl

Note that there can be loss of DNA during sample concentration, as the yields are not 100%. For example, the estimated yield for genomic DNA using the QIAamp DNA Micro Kit is 60%. Using a speed vacuum for concentrating samples is not recommended due to the risk of cross-contamination and increasing the salt in the sample and should only be used when 100% yield is absolutely necessary. If taking this approach, take extra care to ensure that the sample is not completely dried, which can also result in reduced yield.

1. Insufficient amounts of DNA or incorrect concentration. To ensure that samples pass QC, we recommend customers measure sample DNA concentration using the PicoGreen assay as described in the Sample Quality Control Protocol, and ship additional DNA to buffer for any difference in the customer measurement from Complete Genomics’ measurement.
2. Partial degradation. DNA must be provided in 1x TE, pH 8.0. To minimize the likelihood that samples will fail Sample QC due to partial or extensive degradation, we recommend resolving all samples on a 0.8% agarose gel and sharing the results with your Project Manager prior to shipping samples.
3. Improper DNA storage and shipment. Ensure that sample wells are tightly sealed and that the plate is pre-frozen before placing it in the shipping container. Maintain DNA in proper storage conditions (in a -80˚ C freezer) until ready to ship and then ship securely in sufficient dry ice to ensure that the sample does not thaw in transit.