DNA sequencers

A DNA sequencer is an instrument that determines the order of nucleotide bases, adenine, thymine, guanine and cytosine, along a DNA strand. Reading that order lets genetic information be analysed for research, diagnostics and identification work.

The term refers to any machine that reads the base sequence of a DNA sample and outputs it as data. It covers both capillary electrophoresis instruments that read a handful of samples and massively parallel platforms that read billions of fragments per run.

Capillary sequencers separate labelled DNA fragments by size through a gel-filled capillary and read the fluorescent signal at each base. Massively parallel platforms fragment the DNA into a library, amplify it, and read millions to billions of short fragments at once, while single-molecule systems read long fragments directly without amplification.

The main divisions are short-read massively parallel platforms, capillary electrophoresis instruments for Sanger reads, and single-molecule long-read systems. On Questpair the listed types include dna sequencer, high-throughput sequencer, next generation sequencing system and molecular diagnostics instrument, which map onto those three classes.

They are used for whole-genome sequencing, exome and gene panels, RNA-seq, variant confirmation, microbial genomics, forensic and parentage fragment analysis, and clinical molecular diagnostics. Which instrument fits depends on how many samples and what read length the work requires.

Start from throughput: decide how much sequence you need per run and at what read length, because run cost and consumable format follow from that. A capillary system suits a few high-accuracy Sanger reads, while a massively parallel platform suits genomics and large diagnostic panels, and the two are not interchangeable.

A used sequencer is sold in its current condition as it came from the prior lab, while a refurbished unit has been checked and returned to working order before listing. Both are listed below new pricing for comparable builds, so ask for recent run metrics and the consumable version the unit accepts either way.

Prices on Questpair range from EUR 34 to EUR 301.311, with an average near EUR 14.149. The low end covers capillary readers, fragment analysers and components, while the high end covers high-output platforms sold complete, so the figure reflects configuration as much as condition.

The catalogue is led by Illumina, Applied Biosystems, Thermo Fisher Scientific, PacBio and Life Technologies. Illumina and Applied Biosystems cover the short-read and capillary ends, while PacBio represents the long-read class.

A warranty is often possible and is arranged in consultation for the specific listing. Questpair does not set support terms centrally, so check what the individual listing states and raise warranty with the supplier before purchase.

Parts, flow cells and reagent formats for the dominant platforms are among the most widely available because so many listings describe the same model families. Parts can be sourced via Questpair when a specific component is needed.

Lifespan depends on the wear on the optics and fluidics and on whether the platform still accepts a current consumable version. A unit locked to a discontinued reagent kit cannot be fed, so the supportable life is tied to reagent availability as much as to mechanical condition.

Used and refurbished units are listed at lower prices than new ones for comparable configurations, and they make up a large share of this catalogue. Where you need to weigh the two, compare the individual listing and arrange warranty in consultation, since many prior-generation platforms still deliver production-grade data.

Questpair lists DNA sequencers from 11 verified suppliers and distributors across 8 countries. The listings put new, used and refurbished units together so the same model families can be compared side by side.

Lead time and shipping depend on the individual supplier and the location of the unit, which spans 8 countries. The listing or the supplier gives the specific timing, and Questpair specialists respond within an hour where a listing leaves it open.

Routine upkeep covers optics checks, fluidics cleaning, capillary or flow cell replacement, and verifying run metrics such as cluster density, loading efficiency and error rate. Questpair does not perform servicing, but it can source the parts and consumables these procedures require.

Short-read massively parallel platforms sit at the high-throughput end and carry genomics, exome panels and RNA-seq, so genomics and clinical diagnostics labs reach for them. Capillary instruments go to labs doing Sanger confirmation and forensic fragment analysis, while long-read systems serve de novo assembly and transcript isoform work.

Illumina, Applied Biosystems, Thermo Fisher Scientific, PacBio and Life Technologies lead the listings here. That concentration means parts and reagent formats for these platforms are widely available and listings are easy to compare, since so many describe the same model families.

The low end of the range at EUR 34 covers capillary readers, fragment analysers and bare components, while the top at EUR 301.311 covers complete high-output production platforms. The gap reflects throughput and configuration first, then condition, with used and refurbished units listed below new for comparable builds.