 It was the first manuscript of great importance and antiquity of which any extensive use was made by textual critics , but the value of the codex was differently appreciated by different writers in the past . Wettstein created a modern system of <unk> of the New Testament manuscripts . Codex Alexandrinus received symbol A and opened the list of the NT uncial manuscripts . Wettstein announced in his Prolegomena ad Novi Testamenti <unk> ( 1730 ) that Codex A is the oldest and the best manuscript of New Testament , and should be the basis in every reconstruction of the New Testament text . Codex Alexandrinus became a basis for criticizing the Textus Receptus ( Wettstein , Woide , Griesbach ) . 
