Polymerase Chain Reaction (PCR) machines have transformed molecular biology by making it possible to quickly and accurately amplify DNA and RNA. They are now essential tools in genetic testing, disease diagnostics, forensic analysis, and food safety, serving both research and clinical laboratories worldwide. This guide explains the principles, components, and working of PCR machines, while outlining their types, applications, advantages, and limitations. It also reviews leading brands, pricing trends, and financing options, providing readers with a complete overview of how PCR technology drives scientific progress and supports modern healthcare.
What is a PCR machine?
A PCR (Polymerase Chain Reaction) machine is a laboratory instrument used to amplify small segments of DNA or RNA. It facilitates the rapid and precise replication of genetic material, enabling various molecular biology applications such as gene cloning, sequencing, and disease diagnosis.
Principle of PCR machines
The principle of Polymerase Chain Reaction (PCR) involves amplifying specific DNA sequences. The process begins with denaturation, where the double-stranded DNA is heated to separate into single strands. This is followed by annealing, where short DNA primers bind to each strand at lower temperatures. The final step is extension, where the enzyme taq polymerase synthesises new DNA strands by adding nucleotides to the primers. These steps are repeated through cycles, exponentially increasing the DNA amount. PCR requires a thermal cycler machine to precisely control temperature changes, allowing rapid and efficient DNA amplification, which is crucial for various applications in research and diagnostics.
Parts and components of a PCR machine
A PCR machine, also known as a thermocycler, consists of several key components:
- Thermal block: Holds samples in tubes or plates and facilitates temperature changes.
- Heated lid: Prevents condensation on tube lids by maintaining a constant temperature.
- Control panel: Interface for programming and controlling PCR cycles and temperatures.
- Display screen: Shows current status, temperature, and cycle progress.
- Peltier heating/cooling units: Enable rapid and precise temperature changes for denaturation, annealing, and extension.
- Air intake and ventilation: Ensures proper air circulation to maintain consistent internal temperatures.
- Sample Wells: Receptacles in the thermal block for holding PCR tubes or microplates.
- Power supply: Provides electrical energy to the machine and its components.
To ensure effective diagnostics, labs often use other essential devices like the dialysis machines for testing and patient care workflows.
PCR machine core steps
PCR machines follow three fundamental steps, repeated across multiple cycles to achieve DNA amplification:
Denaturation: The DNA sample is heated to about 94–98°C, breaking the hydrogen bonds between the two strands and separating them into single strands.
Annealing: The temperature is reduced to around 50–65°C, enabling short DNA primers to attach to their complementary sequences on the single-stranded templates.
Extension: The temperature is increased to nearly 72°C, the ideal range for DNA polymerase activity. Starting at the bound primers, the enzyme synthesises a new complementary DNA strand by adding free nucleotides.
Just as advanced equipment like a medical ventilator machine plays a critical role in healthcare, PCR machines are equally vital in molecular diagnostics, ensuring precision in research and clinical outcomes.
PCR steps
PCR involves three main steps repeated in cycles:
Denaturation
- The mixture is heated to 94°C for 0.5 to 2 minutes.
- This heat breaks the hydrogen bonds between DNA strands, turning them into single strands.
- The single strands serve as templates for creating new DNA strands.
Annealing
- The temperature is lowered to 54-60°C for 20-40 seconds.
- Primers, which are short DNA or RNA sequences, bind to the complementary sequences on the single-stranded DNA.
- Each separated strand gets a forward and reverse primer.
Elongation
- The temperature is raised to 72-80°C.
- The taq polymerase enzyme adds DNA bases to the 3' end of the primer, extending the DNA strand in the 5' to 3' direction.
- This enzyme can withstand high temperatures and works quickly, adding about 1000 bases per minute.
These three steps are repeated 20-40 times to rapidly amplify the target DNA sequences. In clinical settings, accurate PCR results can complement life-support equipment like a medical ventilator machine in critical care scenarios.
What does a PCR machine do?
PCR machines perform polymerase chain reactions, which involve three main steps: denaturation, annealing, and extension. During denaturation, the DNA strands are heated to separate into single strands. In annealing, primers bind to complementary sequences, and in extension, DNA polymerase synthesizes new strands using nucleotides.
How do PCR machines work
PCR machines operate based on thermal cycling, which involves repeatedly heating and cooling the reaction mixture to facilitate DNA replication. The machine comprises a thermal block or well plate where samples undergo temperature changes according to programmed protocols. PCR involves multiple cycles of denaturation, annealing, and extension, typically controlled by computer software. Fluorescent dyes or probes may be used for real-time PCR to monitor amplification in real-time. Alongside PCR, surgeons and lab technicians may also rely on precision tools such as a cautery machine for controlled tissue work during sample collection.
PCR machine operating procedure
- Prepare reaction mixture with DNA template, primers, nucleotides, and DNA polymerase.
- Load the reaction mixture into PCR tubes or wells of a thermal block.
- Program PCR machine with desired temperature cycles.
- Initiate PCR run and monitor amplification progress.
- Analyze results using gel electrophoresis or real-time monitoring.
Types of PCR machines
- Conventional PCR machines
- Real-time PCR machines
- Digital PCR machines
PCR machine applications
- Genetic testing
- Disease diagnosis
- Forensic analysis
- Environmental monitoring
- Food safety testing
PCR machine advantages
- Rapid amplification of DNA/RNA
- High specificity and sensitivity
- Versatile applications
- Automation capability
- Real-time monitoring options
PCR machine limitations
- Susceptibility to contamination
- Limited throughput in conventional PCR
- Initial setup and maintenance costs
- Dependency on primer design and specificity
Precautions using PCR machine
- Use sterile techniques to prevent contamination.
- Regularly clean and maintain equipment.
- Follow manufacturer's instructions for protocol setup.
- Implement proper safety measures when handling PCR reagents.
PCR machine examples
PCR machines vary by brand and underlying technology. Below are some commonly used models in laboratories:
Examples by Brand
Bio-Rad: T100 (ideal for classrooms), CFX96 Real-Time PCR System (suited for high-throughput analysis)
Applied Biosystems (Thermo Fisher Scientific): VeritiPro Thermal Cycler, QuantStudio 5 Real-Time PCR System
QIAGEN: Rotor-Gene Q (real-time PCR), QIAcuity (digital PCR platform)
Eppendorf: Mastercycler series (widely used for general PCR amplification)
Examples by Technology
Thermal Cyclers: Bio-Rad T100, Eppendorf Mastercycler
Real-Time PCR (qPCR): Bio-Rad CFX96, QIAGEN Rotor-Gene Q
Digital PCR (dPCR): QIAGEN QIAcuity
Multi-block & Portable Systems: Biometra TAdvanced, Drawell Gentier-Mini
How much does a PCR machine cost?
PCR machine costs vary depending on the type, brand, features, and specifications. Basic models may start from a few thousand pounds, while high-end real-time PCR machines can cost tens of thousands of pounds. Dependency on primer design and specificity. To maintain optimal lab environments and reduce sample degradation, facilities often use devices like an oxygen making machine to regulate air quality.
Leasing vs. buying PCR machines
- Leasing offers flexibility with lower initial costs and convenient upgrades.
- Buying provides ownership benefits and long-term cost savings but requires higher upfront investment.
PCR machine prices
PCR machine prices can vary significantly based on features and brand. Entry-level models may start around ₹1.5 lakh, while advanced units can exceed ₹10 lakh. Factors influencing the cost include throughput capacity, automation features, and detection methods. Investing in a reliable PCR machine ensures accurate and efficient DNA amplification, making it a crucial asset for research labs, medical diagnostics, and biotechnology companies. Recent innovations are pushing boundaries in molecular diagnostics, integrating technologies like nano machines for improved control and miniaturization.
Buy PCR equipment from the top brands
Brand |
Price range (INR) |
Key features |
SD Bio sensor |
Rs.8.5 lakh - Rs.19 lakh |
Advanced technology, high precision, reliable support |
Thermo Fisher |
Varies |
Cutting-edge technology, robust performance |
Bio-Rad |
Varies |
Exceptional customer support, durability |
Financing options for purchasing PCR machines
Explore medical equipment finance options, including loans and leasing, to acquire PCR machines conveniently. Bajaj Finance offers tailored medical equipment solutions to suit your requirements.
Conclusion
A PCR (Polymerase Chain Reaction) machine, or thermocycler, is a vital laboratory instrument used to amplify DNA and RNA sequences for applications across genetics, diagnostics, forensics, and scientific research. Based on thermal cycling principles, it performs precise denaturation, annealing, and extension of DNA strands. Different types are available, including conventional, real-time, and digital PCR machines, each designed for specific requirements. While they offer advantages such as high sensitivity, quick turnaround, and automated operation, they also present challenges like risk of contamination and relatively high costs. Prices can vary considerably, with many suppliers offering leasing and financing arrangements for greater flexibility.
For healthcare professionals and institutions looking to purchase or upgrade PCR machines, Bajaj Finance provides convenient financing solutions such as doctor loans, professional loans, and hospital loans, helping ensure that essential medical equipment is accessible without added financial burden.
