Tamanho produto PCR
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
Reverse - Forward
About this calculator
The PCR product size calculator determines the length of DNA amplified during polymerase chain reaction (PCR). It works by subtracting the forward primer position from the reverse primer position, using the formula: Size = Reverse - Forward. This provides the segment of DNA to be amplified, based on their base pair locations.
This tool is crucial in genetic studies, cloning, and sequencing where precise PCR product lengths are required. For instance, in mutation analysis or gene expression experiments, accurate calculations ensure the amplified fragment matches the target region. Always confirm that primers are correctly placed in the genome to avoid negative or inaccurate results.
If the calculation yields a negative result, it indicates an error in primer order: the reverse primer is before the forward primer, which is invalid. Additionally, poorly designed primers may lead to unintended amplification. Use this calculator as a guide, but complement it with specialized primer design software for higher reliability.
Frequently asked questions
How is PCR product size calculated?
It is calculated by subtracting the forward primer position from the reverse primer position (Size = Reverse - Forward), giving the length of the amplified DNA fragment.
Why might the result be negative?
A negative result occurs when the reverse primer is positioned before the forward primer in the genome, which is invalid and indicates an ordering error.
What is PCR product size used for?
It helps plan genetic experiments like cloning, sequencing, and mutation analysis by ensuring the amplified fragment matches the target region.
Do I need additional software to use this calculator?
Not mandatory, but primer design tools like Primer3 can validate primer positions and improve calculation reliability.