 B. J. Hoffman

B. J. Hoffman coauthored the 1983 cDNA library method with U. Gubler. Their procedure connected first-strand copying of messenger RNA with an enzymatic second-strand synthesis step, simplifying recovery of double-stranded DNA copies.^[ref] The paper establishes this collaborative contribution; it does not assign every laboratory step to an individual author.

A particularly informative validation used a previously sequenced bovine transcript and tested the recovered copies by sequencing. The abstract reports faithful full-length products for that test.^[ref] Sequence comparison addresses what the method preserved, rather than merely showing that DNA material was produced.

An original probability example separates two quality questions. Let $F$ mean that a recovered copy is full length, and $C$ mean that its sequence meets a stated correctness criterion. ThenIf a stipulated preparation has $P(F)=0.80$ and $P(C\mid F)=0.95$, the fraction satisfying both criteria is 0.76. Multiplying marginal probabilities would require an additional independence assumption; the conditional expression does not.

For a cDNA library, a product can therefore have plausible length but sequence changes, or correct sequence over a shorter region while lacking an end. Validation should state which region was read and which criterion was tested. An illustrative 100-copy sample with 80 full-length products and 76 meeting both conditions has 95 percent correctness among the full-length products but 76 percent joint success across all recovered copies. These numbers explain the distinction and are not measurements from the original study.

Hoffman's initials remain as printed. The verified molecular-method contribution is sufficient to describe the research without inventing personal dates, an expanded name or a portrait.