The manuscript is a
codex (precursor to the modern book) made from 773
vellum folios (specific name for pages in a codex) measuring , bound in
quarto format (parchment leaves placed on top of each other, folded in half vertically, and then folded in half again horizontally, to make a single block, then stitched together with others to create a book), which now comprise four volumes. Most of the folios were originally gathered into
quires of eight leaves each (this being eight parchment leaves placed on top of each other, then folded as per
quarto above). Scholar B. H. Cowper describes the vellum as "thin, fine, and very beautiful". In modern times it was rebound into sets of six leaves each. Cowper's further description of the pages note they are "often discoloured at the edges", which have been damaged by age and more so through "the ignorance or carelessness of the modern binder, who has not always spared the text, especially at the upper inner margin". Scrivener noted that "[t]he vellum has fallen into holes in many places, and since the ink peels off for every age whensoever a leaf is touched a little roughly, no one is allowed to handle the manuscript except for good reasons." Three volumes contain the
Septuagint (the Greek version of the Old Testament, also known as the LXX), of which the total count of folios for each volume is 279, 238, and 118 with ten leaves lost. The fourth volume contains the New Testament in the remaining 144 folios, with 31 leaves lost. In the fourth volume,
1 and
2 Clement are also missing leaves, perhaps 3. The text in the codex is written in two columns in
uncial script, with between 49 and 51 lines per column, and 20 to 25 letters per line. The beginning lines of each book are written in red ink, and sections within the book are marked by a larger letter set into the margin. The text is written continuously, with no division of words (known as
Scriptio continua), but some pauses are observed in places in which a dot should be between two words. There are no
accents or
breathing marks, except a few added by a later hand. The punctuation was written by the first hand. The poetical books of the Old Testament are written
stichometrically (this being a new verse/phrase starting on a new line). The Old Testament quotations in the text of New Testament are marked in the margin by the sign 〉(known as a
diplai). The only decorations in the codex are tail-pieces at the end of each book (see illustration), and it also shows a tendency to increase the size of the first letter of each sentence. The larger letters at the beginning of the sections stand out in the margin as in codices
Ephraemi and
Basilensis. Codex Alexandrinus is the oldest manuscript to use larger letters to indicate new sections.
Iotacistic errors occur in the text: αὶ is exchanged for ε, εὶ for ὶ and η for ὶ. This is, however, no more than seen in other manuscripts of the same date. The letters
Ν and
Μ are occasionally confused, and the cluster (gg) is substituted with (ng). This may be an argument which points to Egypt as where the codex was produced, but it is not universally accepted. The handwriting from the beginning of Luke to 1 Corinthians 10:8 differs from that in the rest of the manuscript. Some letters have
Coptic shapes (f.e.
Α (alpha),
Μ (mu),
Δ (delta), and
Π (pi)). The letters are more widely spaced and are a little larger than elsewhere. Δ has extended base and Π has extended cross-stroke.
Numerals are not expressed by letters except in
Revelation 7:4; 21:17. In the past the codex had been judged to have been carelessly written, with many errors of transcription, but not so many as in
Codex Sinaiticus, and no more than
Codex Vaticanus. The
majuscule letters have elegant shape, but a little less simple than those in
Codex Sinaiticus and
Codex Vaticanus. At the end of a line, these letters are often very small, and much of the writing is very pale and faint. Punctuation is more frequent, usually on a level with the top of the preceding letter, while a vacant space, proportionate to the break in the sense, follows the end of a paragraph. At the end of each book the
colophon is ornamented by pretty
volutes from the initial copyist. The
Ammonian Sections with references to the
Eusebian Canons (an early system of dividing the four Gospels into different sections, developed by early church writer
Eusebius of Caesarea) stand in the margin of the Gospels. It contains divisions into larger sections (known as (
kephalaia), or
chapters), the headings of these sections (known as /
titloi) stand at the top of the pages. The places at which sections start are indicated throughout the Gospels, and in Luke and John their numbers are placed in the margin of each column. To all the Gospels (except
Matthew, due to several pages missing at the beginning) is prefixed by a table of contents (also known as ). The various
Euthalian Apparatus sections into which the Acts, Epistles, and Apocalypse were divided (similar to
Eusebius' system for the Gospels) are not indicated in this manuscript. A
cross appears occasionally as a separation in the
Book of Acts. A larger letter in the margin throughout the New Testament marks the beginning of a paragraph. The number of scribes who worked on the codex has been disputed. According to biblical and classical scholar
Frederic Kenyon there were five scribes, two scribes in the Old Testament (I and II) and three in the New (III, IV, and V). Subsequently, textual critics
Theodore Skeat and Milne argued there were only two or possibly three scribes, a view widely accepted by 20th-21st century scholars(such as biblical scholar and textual critic
Bruce Metzger, biblical scholar and textual critic
Kurt Aland, textual critic Juan Hernández Jr., and textual critic Dirk Jongkind). Many corrections have been made to the manuscript, some of them by the original scribe, but the majority of them by later hands. The corrected form of the text agrees with that seen in
Codex Bezae (D),
Codex Petropolitanus Purpureus (N),
Codex Monacensis (X),
Codex Macedoniensis (Y),
Codex Tischendorfianus IV (Γ),
Codex Koridethi (Θ),
Codex Petropolitanus (Π),
Codex Rossanensis (Σ),
Codex Beratinus (Φ) and the majority of minuscule manuscripts. Kenyon observed that Codex Alexandrinus had been "extensively corrected, though much more in some books than in others". In the Pentateuch, whole sentences were erased and a new text substituted. Kings was the least corrected of the books. In the Book of Revelation only 1 of its 84 singular readings was corrected, the rest remained uncorrected. This is in stark contrast with
Codex Sinaiticus, in which 120 of the Apocalypse's 201 singular readings were corrected in the 7th century. Each leaf has Arabic numeration, set in the verso of the lower margin. The first surviving leaf of Matthew has number 26. The 25 leaves now lost must have been extant when that note was written. ==Contents==