Disclosed is a multi-stage thermal convection apparatus such as a two-stage thermal convection apparatus and uses thereof. In one embodiment, the two-stage thermal convection apparatus includes a temperature shaping element that assists a thermal convection mediated Polymerase Chain Reaction (PCR). The invention has a wide variety of applications including amplifying nucleic acid without cumbersome and expensive hardware associated with many prior devices. In a typical embodiment, the apparatus can fit in the palm of a user's hand for use as a portable, simple to operate, and low cost PCR amplification device.

The invention relates to a method for the amplification of nucleic acids by means of a polymerase chain reaction in a reaction volume, wherein the reaction volume is heated by using electrical energy. In at least one of the passages of the amplification cycle of the polymerase chain reaction, the ratio of the electrical energy used in the denaturation step to heat the reaction volume to the size of the reaction volume is less than 20 Joule per millilitre. The invention further relates to the use of a device comprising a reaction vessel for receiving the reaction volume and a heating means consisting of one or a plurality of heating elements (1), which are in contact with the reaction volume in order to heat it, wherein at least one of the heating elements is conjugated to oligonucleotides (5), for the amplification of nucleic acids in a reaction volume. Lastly, the invention relates to a device for the amplification of nucleic acids in a reaction volume, which comprises a reaction vessel for receiving the reaction volume, and a heating means consisting of one or a plurality of heating elements (1), which are in contact with the reaction volume in order to heat it.

Analyte detection systems and related methods are generally described. In some embodiments, an analyte testing system may rapidly and sensitively sense analyte (e.g., any biological and/or chemical analyte) from a testing sample in a fluid container, which may also include one or more populations of particles coated with/including binding ligands, moieties, and/or coatings for binding to analyte, if present. An external force may be applied to the container to urge the particles to move through the fluid faster than a rate determined by diffusion. The particles may subsequently settle on a target surface. The particles disposed on the surface may be characterized to determine the presence of the analyte. In some embodiments, a sequence of images of particles bound specifically and nonspecifically to the surface may be analyzed to determine a relative displacement of the particles, and subsequently, analyte concentration of the testing sample.

A method for extracting a target nucleic acid from a sample liquid includes providing a heating device having a heating element in contact with the sample liquid. The heating element is conjugated with at least one functional nucleic acid. The functional nucleic acid is adapted to hybridize to the target nucleic acid and bind the target nucleic acid to the heating element. Further, the method includes generating relative movement between the heating element and the sample liquid and extracting the target nucleic acid from the sample liquid by separating the heating element from the sample liquid.