Genomics Researchers Showcase their Applications of Droplet Digital PCR at ASHG 2017 Annual Meeting
News Oct 18, 2017
The sensitivity and reliability of Droplet Digital PCR will be showcased in over a dozen presentations at the American Society of Human Genetics (ASHG) 2017 Annual Meeting, Orlando, Fla., October 17-21. The breadth and diversity of the posters and plenaries demonstrate the impact Droplet Digital PCR technology has had throughout genomics.
"It's gratifying to see the applications we proposed for Droplet Digital PCR in 2011 go from being theory to reality," said George Karlin-Neumann, Director of Scientific Affairs for Bio-Rad's Digital Biology Group. "Researchers trust Droplet Digital PCR technology for absolutely quantifying gene expression, measuring cell-free DNA, detecting rare mutations, and many other uses."
Featured Talks and Demonstrations
Rare Mutation Detection Maintains Stem Cell Integrity
Stem cell therapies that are being developed with induced pluripotent stem cells (iPSCs) must be evaluated for safety risks before they reach the clinic as mutations may develop in the process of reprogramming and culturing iPSCs. Researchers at Kyoto University, Japan, led by Professor Naoko Takasu, are using Droplet Digital PCR to identify cells whose mutations might harm a potential patient.
"We need to be able to identify any cancer-related de novo mutations, even if they occur at extremely low frequencies," said Tomoko Takahashi, PhD, a member of Prof. Takasu's group.
The task requires a sensitive and specific technology. In her presentation, Takahashi will share how her group developed and validated a Droplet Digital PCR assay to detect a mutant allele with frequency as low as 0.5%. Takasu's group plans to use the method to identify rare structural variants and mosaicism among iPSCs and differentiated cell populations in future stem cell studies.
This poster (abstract #410) will be presented on Thursday, October 19, from 3-4 PM during the Gene Structure and Function session.
Cell-Free DNA Measurement Non-Invasively Detects Transplant Rejection
The standard method for diagnosing lung transplant rejection is invasive and expensive. To develop a far less invasive alternative, Andrew Young and colleagues at Washington University in St. Louis are using Droplet Digital PCR technology to quantify donor-derived cell-free DNA (cfDNA), a marker of tissue rejection in blood.
The study used a panel of probes that binds to specific single nucleotide polymorphisms (SNPs) and indels in human leukocyte antigen (HLA) molecules. The team showed that patients with biopsy-proven transplant rejection showed elevated levels of donor-derived cfDNA compared to patients without evidence of rejection.
"Because HLA types differ from each other by known SNPs and small indels, Droplet Digital PCR analysis may be helpful in determining whether a patient is experiencing lung transplant rejection. The process of collecting this data is far less invasive than transbronchial lung biopsy," Young said.
Young will present his group's findings at a special Bio-Rad Exhibitor Education Event on Thursday, October 19, at 12:30 PM.
Interrogating Cancer Target with Absolute Gene Expression Quantification
Droplet Digital PCR is empowering investigations into potential cancer therapeutics. A team at Umeå University in Sweden, led by Dr. Irina Golovleva, will present research on the KIF23 gene, which is upregulated in many cancers.
A mutated form of KIF23 causes a hereditary form of anemia known as CDA III, and researchers believe this could be due to the mutation's effect on the alternative splicing of KIF23. Using CDA III as a model, Golovleva's team is employing Droplet Digital PCR to understand how alternative splicing of KIF23 may also play a role in cancer.
"Our early Droplet Digital data suggest when the disease-causing mutation is present, expression levels shift, causing the anemic phenotype," said Ann-Louise Vikberg, a PhD candidate in Dr. Golovleva's group.
Making meaningful comparison of KIF23 expression levels across tissues is difficult to do using qPCR as it requires relative quantification of KIF23 with respect to housekeeping gene expression in each of the tissues. Droplet Digital PCR solved this issue with absolute quantification and enabled the Umeå team to directly compare expression levels between different tissues.
This poster (abstract #1693) will be presented on Wednesday, October 18, from 2-3 PM during the Developmental Genetics and Gene Function session.