Haplotype phasing of whole human genomes using bead-based barcode partitioning in a single tube.

Haplotype-resolved genome sequencing promises to unlock a wealth of information in population and medical genetics. However, for the vast majority of genomes sequenced to date, haplotypes have not been determined because of cumbersome haplotyping workflows that require fractions of the genome to be sequenced in a large number of compartments. Here we demonstrate barcode partitioning of long DNA molecules in a single compartment using "on-bead" barcoded tagmentation. The key to the method that we call "contiguity preserving transposition" sequencing on beads (CPTv2-seq) is transposon-mediated transfer of homogenous populations of barcodes from beads to individual long DNA molecules that get fragmented at the same time (tagmentation). These are then processed to sequencing libraries wherein all sequencing reads originating from each long DNA molecule share a common barcode. Single-tube, bulk processing of long DNA molecules with ∼150,000 different barcoded bead types provides a barcode-linked read structure that reveals long-range molecular contiguity. This technology provides a simple, rapid, plate-scalable and automatable route to accurate, haplotype-resolved sequencing, and phasing of structural variants of the genome.

Profound Autonomic Instability Complicated by Multiple Episodes of Cardiac Asystole and Refractory Bradycardia in a Patient with Anti-NMDA Encephalitis.

Anti-N-methyl-d-aspartate receptor encephalitis (anti-NMDARE) is autoimmune encephalitis primarily affecting young adults and children. First described about a decade ago, it frequently manifests as a syndrome that includes progressive behavioral changes, psychosis, central hypoventilation, seizures, and autonomic instability. Although cardiac arrhythmias often accompany anti-NMDARE, the need for long-term electrophysiological support is rare. We describe the case of NMDARE whose ICU course was complicated by progressively worsening episodes of tachyarrhythmia-bradyarrhythmia and episodes of asystole from which she was successfully resuscitated. Her life-threatening episodes of autonomic instability were successfully controlled only after the placement of a permanent pacemaker during her ICU stay. She made a clinical recovery and was discharged to a skilled nursing facility after a protracted hospital course.

Highly parallel oligonucleotide purification and functionalization using reversible chemistry.

We have developed a cost-effective, highly parallel method for purification and functionalization of 5'-labeled oligonucleotides. The approach is based on 5'-hexa-His phase tag purification, followed by exchange of the hexa-His tag for a functional group using reversible reaction chemistry. These methods are suitable for large-scale (micromole to millimole) production of oligonucleotides and are amenable to highly parallel processing of many oligonucleotides individually or in high complexity pools. Examples of the preparation of 5'-biotin, 95-mer, oligonucleotide pools of >40K complexity at micromole scale are shown. These pools are prepared in up to ~16% yield and 90-99% purity. Approaches for using this method in other applications are also discussed.