Final answer:
The question appears to be unrelated to biology or PCR primer design as it mentions a temperature range (70F-80F) not typically used for nucleotide primers. Correct storage time for chemical primers should be obtained from manufacturer's instructions or specific lab protocols.
Step-by-step explanation:
From the context provided, this question does not appear to correspond to biology or primer designing for PCR as initially suggested. In the field of polymerase chain reaction (PCR), primers, which are short strands of nucleotides, indeed should be designed to have certain lengths and melting temperatures. However, the question pertains to a temperature range of 70F to 80F, which does not align with molecular biology protocols. Instead, without specific guidance from product instructions or scientific protocols, one cannot accurately determine the correct storage time for primers at these temperatures. It is essential to follow the manufacturer's recommendations for the use and storage of specific chemical primers. If the information came from a product instruction or lab manual guideline, one should refer directly to those specific instructions as they can vary by product.