Sequencing methods were used to test the integrity of the cDNA library and when this was done you found many of the sequences were those found in introns.After troubleshooting you determined that the reason these intronic sequences were present was because during the construction of this cDNA library:
A)genomic DNA was present.
B)retroviral DNA was a contaminant.
C)endonucleases should have been added.
D)RNA polymerase was present.

Question

Quizplus · Accepted Answer

The presence of intronic sequences in a cDNA library indicates that genomic DNA was present during the construction process. Intron sequences are not present in mature RNA and are only found in genomic DNA. Therefore, if intron sequences are present in a cDNA library, it suggests that reverse transcription enzymes used to create the cDNA library were not specific enough to only capture mRNA molecules and failed to differentiate between mRNA and genomic DNA. This can lead to contamination of the cDNA library with intronic sequences.

Sequencing Methods Were Used to Test the Integrity of the CDNA