Biochip

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Biochip

Biochips are small devices that act like tiny laboratories. They host hundreds or thousands of biochemical tests on a flat surface, letting scientists run many analyses at once. They help with disease diagnosis, detecting harmful agents, and studying genes and proteins. A biochip system usually includes the sensor on the chip, a way to convert the test result into a signal (like light or electricity), and software to read and interpret the data.

History and idea
- Early sensors, such as the glass pH electrode, laid the groundwork in the 20th century.
- Advances in DNA reading, including PCR in the 1980s and fluorescent tagging, made DNA sensing practical.
- In the 1990s, DNA microarrays were developed to place many DNA sensors on a single surface, popularized later by Affymetrix’s GeneChip.
- Modern biochips combine sensing, surface chemistry, and signal processing to output readable results.

What a biochip is made of and how it’s made
- The core is a dense grid of sensors on a substrate (glass, silicon, or polymer).
- Sensors can detect DNA, proteins, antibodies, or other molecules.
- Manufacturing can be serial (one sensor at a time) or parallel (lots of sensors at once). Some methods use light-directed synthesis to create many DNA sensors on a surface; others use random bead-based approaches with unique signals to identify sensors.

Types of biochips
- DNA microarrays: measure gene expression, genetic variation, and gene function.
- Protein chips: detect proteins and protein interactions.
- Lab-on-a-chip (LOC): combines sample preparation, reaction, analysis, and detection on one chip for quick diagnostics.
- Cell chips: grow and study living cells for drug testing.
- Microfluidic chips: control tiny amounts of liquids for tasks like PCR, cell sorting, and DNA sequencing.

Applications
- Medical diagnostics: quickly detect diseases, infections, and genetic disorders from blood, saliva, or tissue.
- Drug development and personalized medicine: screen many drug candidates and identify biomarkers for tailored treatments.
- Genomics and proteomics: study gene expression and protein interactions on a large scale.
- Environmental monitoring: test water, air, and soil for contaminants on-site.
- Agriculture: assess crops and soil health to improve breeding and disease prevention.

Biochips bring powerful, high-throughput testing to compact, integrated platforms.