His first publication was (1857) the edition (5 quarto volumes) of the Vatican manuscript (B) of the Scriptures prepared by Cardinal Mai under the auspices of Leo XII and printed from 1828 to 1838, to which he added by way of preface a letter to the reader.
Yet critics persisted in thinking a new and accurate edition of the "Vaticanus" was imperatively needed, and Pius IX manifested his intention to carry out the design and entrust it to Vercellone.
Vercellone's critical studies on the text of the Latin Vulgate, although he brought the work only as far as IV Kings, contributed more to his fame than the editing of the Vatican manuscript.
These studies, with important and valuable prolegomena, appeared (2 volumes, 1860–64) under the title, "Variae lectiones Vulgatae latinae editionis Bibliorum", and may be said to have paved the way for the revision of the Vulgate.
As preparatory to his edition of the Greek Bible, Vercellone wrote "Ulteriori studii sul N. T. greco dell' antichissimo Cod.