A universal adapter used in a DNA sequencing run starts 5′-AGTACCG…, with "…" representing many nucleotides.What would be the start of the corresponding universal primer?
A) 5′-AGTACCG…-3′
B) 5′-…TCATGGC-3′
C) 5′-TGTACCG…-3′
D) 5′-…UCAUGGC-3′
E) 5′-AGUUAGU…-3′

Question

Quizplus · Accepted Answer

The corresponding universal primer must be complementary and antiparallel to the adapter sequence. The adapter starts with 5′-AGTACCG…, so the primer that is complementary to this sequence would start with the reverse complement, which is …GGTACT-3′, but since we write sequences from 5′ to 3′, it is written as 5′-…TCATGGC-3′.

A Universal Adapter Used in a DNA Sequencing Run Starts