Abstract:
Methods and apparatus relating to FET arrays including large FET arrays for monitoring chemical and/or biological reactions such as nucleic acid sequencing-by- synthesis reactions. Some methods provided herein relate to improving signal (and also signal-to-noise ratio) from released hydrogen ions during nucleic acid sequencing reactions.
Abstract:
An apparatus may include an array of sensors, a plurality of microwells, a row addressing circuit, a column addressing circuit, and analog-to-digital converters. Each sensor includes a two-transistor circuit with a chemically-sensitive field effect transistor (chemFET) and a row select transistor and each chemFETs has a floating gate structure and a passivation material located over at least a subset of the floating gate structures. The microwells define a plurality of cavities disposed over at least a portion of the floating gate structures and are of a size and shape capable of retaining analyte therein. The column addressing circuit is suitable for supplying output from each sensor in the array of sensors. The analog-to-digital converters are used for each column in the sensor array to convert an analog output of the column addressing circuit to digital form.
Abstract:
Methods and apparatus relating to FET arrays including large FET arrays for monitoring chemical and/or biological reactions such as nucleic acid sequencing-by-synthesis reactions. Some methods provided herein relate to improving signal (and also signal to noise ratio) from released hydrogen ions during nucleic acid sequencing reactions.
Abstract:
A circuit may include an array of CMOS-fabricated pixels formed in columns and rows. Each pixel (105) includes: a chemically-sensitive field effect transistor (chemFET) (150), a first switch (Q3), and a second switch (Q2). The chemFET has a floating gate structure, a source terminal, and a drain terminal that is coupled to a first readout signal line (116). The first switch couples the source terminal of the chemFET to a current source (106) and has one first transistor. The second switch couples the source terminal of the chemFET to a second readout signal line (114) and has one second transistor. The first and second switches are controlled by a row selection line (118) coupled to the two switches.
Abstract:
The invention provides particle compositions having applications in nucleic acid analysis. Nucleic acid polymer particles of the invention allow polynucleotides to be attached throughout their volumes for higher loading capacities than those achievable solely with surface attachment. In one aspect, nucleic acid polymer particles of the invention comprise polyacrylamide particles with uniform size distributions having low coefficients of variations, which result in reduced particle-to-particle variation in analytical assays. Such particle compositions are used in various amplification reactions to make amplicon libraries from nucleic acid fragment libraries.