Base4 Innovation Limited

The Florida State University Research Foundation, Inc.

United Kingdom Research and Innovation

Medical Research Council

Boris Breiner

Barnaby Balmforth

Cameron Alexander Frayling

Thomas Henry Isaac

Bruno Flavio Nogueira De Sousa Soares

Michele Amasio

Alessandra Natale

Paul Dear

Igor Alabugin

Serguei V Kovalenko

Joerg C Schlatterer

Nancy L Greenbaum

Bruno Flavio Soares

Wang Yong Yang

Kerry Gilmore

A microfluidic sequencing device in which a stream of microdroplets at least some of which contain a single nucleotide base are made to undergo reaction with a capture system to capture and detect an ordered sequence of single nucleotide bases generated by progressive pyrophosphorolysis.

Microfluidic device for characterzing polynucleotides

A method for determining the sequence of nucleotide bases in a polynucleotide analyte is provided. It is characterised by the steps of (1) generating a stream of single nucleotide bases from the analyte by pyrophosphorolysis; (2) producing captured molecules by reacting each single nucleotide base with a capture system labelled with detectable elements in an undetectable state; (3) releasing the detectable elements from each captured molecule in a detectable state and (4) detecting the detectable elements so released and determining the sequence of nucleotide bases therefrom. The method can be used advantageously in sequencers involving the use of microdroplets.

Single nucleotide detection method

A method for determining the sequence of nucleotide bases in a polynucleotide analyte is provided. It is characterised by the steps of (1) generating a stream of single nucleotide bases from the analyte; (2) producing captured molecules by reacting each single nucleotide base with a capture system; (3) amplifying at least part of the captured molecule to produce a plurality of amplicons characteristic of the single nucleotide base; (4) labelling the amplicons with a corresponding probe having a characteristic detectable element and (5) detecting a property characteristic of the detectable element.

Disclosed is a method for determining the sequence of nucleotide bases in a polynucleotide analyte characterised by the steps of: a. generating a stream of droplets at least some of which contain a single nucleotide and wherein the order of single nucleotides in the droplet stream corresponds to the sequence of nucleotides in the analyte; b. introducing into each droplet a plurality of biological probe types each type (i) comprising a different detectable element in an undetectable state and (ii) being adapted to capture a different complimentary single nucleotide from which the analyte is constituted; c. causing the single nucleotide contained in the droplet to bind to its complimentary probe to create a used probe; and d. causing the detectable element to be released from the used probe in a detectable state. Typically the biological probe employed comprises a single-stranded nucleotide region the ends of which are attached to two different oligonucleotide regions wherein at least one of the oligonucleotide regions comprises detectable elements having a characteristic detection property and wherein the detectable elements are so arranged on the oligonucleotide region that the detectable property is essentially undetectable in the probe's unused state. In a most preferred embodiment the probe is labelled with multiple fluorophores and further comprises a restriction enzyme recognition site generated by the binding of the target single nucleotide to the single-stranded nucleotide region. Suitably, step c is carried out in the presence of a polymerase and ligase and step d in the presence of a restriction enzyme and an exonuclease. Typically the flow rate of the droplets is 100 to 2000 droplets per second.

Sequencing method

A method for determining the sequence of nucleotide bases in a polynucleotide analyte is provided. It is characterized by the steps of (1) generating a stream of single nucleotide bases from the analyte by pyrophosphorolysis; (2) producing captured molecules by reacting each single nucleotide base with a capture system labelled with detectable elements in an undetectable state; (3) releasing the detectable elements from each captured molecule in a detectable state and (4) detecting the detectable elements so released and determining the sequence of nucleotide bases therefrom. The method can be used advantageously in sequencers involving the use of microdroplets.

Disclosed is a method for sequencing a polynucleotide analyte comprising: &#x2022;a. generating a stream of droplets containing a single nucleotide wherein the order of single nucleotides in the droplet stream corresponds to the sequence of nucleotides in the analyte; &#x2022;b. introducing into each droplet a plurality of biological probe types each type comprising a different label in an undetectable state and being adapted to capture a different single nucleotide; &#x2022;c. causing the single nucleotide contained in the droplet to bind to its complementary probe and &#x2022;d. causing the label to be released from the probe that has bound the nucleotide in a detectable state. The probe is a dumbbell shaped probe comprising fluorescent donor and quencher labels and a single nucleotide gap. After gap repair by a polymerase and a ligase, a restriction enzyme recognition site is cleaved by a restriction enzyme, followed by exonuclease digestion to release the labels.

Compounds and methods for double-stranded DNA cleavage of light-activated lysine conjugates are enhanced at the slightly acidic pH suitable for selective targeting of cancer cells by the presence of two amino groups of different basicities. The first amino group plays an auxiliary role enhancing solubility and affinity to DNA whereas the second amino group which is positioned next to the light-activated DNA-cleaver undergoes protonation at the desired pH threshold. Protonation results in two synergetic effects which account for the increased DNA-cleaving ability at the lower pH: tighter binding to DNA at the lower pH; and the unproductive pathway which quenches the excited state of the photocleaver through intramolecular electron transfer is eliminated once the donor amino group next to the chromophore is protonated. The utility of these molecules for phototherapy of cancer is confirmed by the drastic increase in toxicity of five conjugates against cancer cell lines upon photoactivation.

C-lysine conjugates as pH-controlled, light-activated reagents for double stranded DNA cleavage and associated methods

A process of forming a double strand cleavage in DNA includes providing a reaction mixture containing double stranded DNA having a break in a first strand defining a target site in a second strand. The method continues by adding to the reaction mixture a photoreactive lysine conjugate selected from a lysine-enediyne conjugate, a lysine-acetylene conjugate or a combination thereof, for a time sufficient for the lysine conjugate to bind to the DNA adjacent the target site. The reaction mixture is then irradiated with electromagnetic radiation sufficient to photoactivate the lysine conjugate to cleave the second strand adjacent the target site.

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Cambridge, United Kingdom

Boris Breiner