DNA to mRNA Converter: Fast Sequence Transcription
What this DNA to mRNA converter does
This calculator converts a DNA sequence into an mRNA sequence in the biologically standard direction of 5' → 3'. It also validates your input, reports key metrics (length and GC%), and presents the results in an exportable table.
DNA strands and why the strand choice matters
DNA is double-stranded. During transcription, RNA polymerase reads the template (antisense) strand in the 3' → 5' direction and synthesizes mRNA in the 5' → 3' direction. Sometimes, sequences are provided as the coding (sense) strand, which matches mRNA except that DNA uses T while RNA uses U.
How the conversion is calculated
1) Coding (sense) strand input
If you provide the coding strand in 5' → 3', the mRNA is computed by replacing thymine with uracil:
\( \text{mRNA} = \text{DNA}_{coding} \text{ with } T \rightarrow U \)
2) Template (antisense) strand input
If you provide the template strand, the mRNA is computed by complementary base pairing (after ensuring the template is oriented 3' → 5'):
\[ A \rightarrow U,\quad T \rightarrow A,\quad C \rightarrow G,\quad G \rightarrow C \]
Simple vs detailed table views
Simple mode lists a row per nucleotide, which is useful for verifying base-by-base transcription.
Detailed mode groups results into codons (triplets) and flags common signals such as:
\( \text{Start codon} = AUG \)
\( \text{Stop codons} = UAA,\; UAG,\; UGA \)
GC percentage and other metrics
The GC percentage is computed from the mRNA sequence:
\[ GC\% = \left(\frac{\#(G) + \#(C)}{\text{mRNA length}}\right)\times 100 \]
The calculator also reports the number of full codons as:
\[ \text{Full codons} = \left\lfloor \frac{\text{mRNA length}}{3} \right\rfloor \]
Input validation rules
Valid DNA bases are A, T, C, and G. If invalid characters exist, you can either stop with an error or remove them before transcription. This helps avoid silent mistakes when copying sequences from documents or spreadsheets.