The present disclosure relates to methods for determining a viral titer of a biological sample, suitably from a mammalian cell sample. The methods include the use of mechanical disruption of the cells, followed by droplet digital polymerase chain reaction (ddPCR) to determine the viral titer. Methods of mechanical disruption suitably include the use of glass beads.

The present disclosure relates to methods for determining a viral titer of a biological sample, suitably from a mammalian cell sample. The methods include the use of mechanical disruption of the cells, followed by droplet digital polymerase chain reaction (ddPCR) to determine the viral titer. Methods of mechanical disruption suitably include the use of glass beads.

The present disclosure generally relates, in certain aspects, to droplet-based microfluidic devices and methods. In certain aspects, target nucleic acids contained within droplets are amplified within droplets in a first step, where multiple primers may be present. However, multiple primers may cause multiple target nucleic acids to be amplified within the droplets, which can make it difficult to identify which nucleic acids were amplified. In a second step, the amplified nucleic acids may be determined. For example, the droplets may be broken and the amplified nucleic acids can be pooled together and sequenced. As an example, new droplets may be formed containing the amplified nucleic acids, and those nucleic acids within the droplets amplified by exposure to certain primers.

The present disclosure generally relates, in certain aspects, to droplet-based microfluidic devices and methods. In certain aspects, target nucleic acids contained within droplets are amplified within droplets in a first step, where multiple primers may be present. However, multiple primers may cause multiple target nucleic acids to be amplified within the droplets, which can make it difficult to identify which nucleic acids were amplified. In a second step, the amplified nucleic acids may be determined. For example, the droplets may be broken and the amplified nucleic acids can be pooled together and sequenced. As an example, new droplets may be formed containing the amplified nucleic acids, and those nucleic acids within the droplets amplified by exposure to certain primers.

This disclosure provides methods and compositions for sample processing, particularly for sequencing applications. Included within this disclosure are bead compositions, such as diverse libraries of beads attached to large numbers of oligonucleotides containing barcodes. Often, the beads provides herein are degradable. For example, they may contain disulfide bonds that are susceptible to reducing agents. The methods provided herein include methods of making libraries of barcoded beads as well as methods of combining the beads with a sample, such as by using a microfluidic device.

This disclosure provides methods and compositions for sample processing, particularly for sequencing applications. Included within this disclosure are bead compositions, such as diverse libraries of beads attached to large numbers of oligonucleotides containing barcodes. Often, the beads provides herein are degradable. For example, they may contain disulfide bonds that are susceptible to reducing agents. The methods provided herein include methods of making libraries of barcoded beads as well as methods of combining the beads with a sample, such as by using a microfluidic device.

The disclosure provides for methods, compositions, and kits for multiplex nucleic acid analysis of single cells. The methods, compositions and systems may be used for massively parallel single cell sequencing. The methods, compositions and systems may be used to analyze thousands of cells concurrently. The thousands of cells may comprise a mixed population of cells (e.g., cells of different types or subtypes, different sizes).

The disclosure provides for methods, compositions, and kits for multiplex nucleic acid analysis of single cells. The methods, compositions and systems may be used for massively parallel single cell sequencing. The methods, compositions and systems may be used to analyze thousands of cells concurrently. The thousands of cells may comprise a mixed population of cells (e.g., cells of different types or subtypes, different sizes).

A nucleic acid amplification method includes a step of heating a first region of a container housing a droplet containing a target nucleic acid and a sample necessary for amplification of the target nucleic acid to a denaturation temperature of the target nucleic acid and heating a second region different from the first region to a synthesis temperature of the target nucleic acid, and an amplification step of repeating a cycle through a denaturation stage at which the droplet housed in the container is moved to and retained in the first region and a synthesis stage at which the droplet is moved to and retained in the second region at a plurality of times. At the amplification step, periods of part of cycles of the plurality of cycles are made shorter than periods of the other cycles.

A nucleic acid amplification method includes a step of heating a first region of a container housing a droplet containing a target nucleic acid and a sample necessary for amplification of the target nucleic acid to a denaturation temperature of the target nucleic acid and heating a second region different from the first region to a synthesis temperature of the target nucleic acid, and an amplification step of repeating a cycle through a denaturation stage at which the droplet housed in the container is moved to and retained in the first region and a synthesis stage at which the droplet is moved to and retained in the second region at a plurality of times. At the amplification step, periods of part of cycles of the plurality of cycles are made shorter than periods of the other cycles.