1 Ph.D.-12 phage display library (X12) 12 ~1.0e9 ~1.0e13 New England BioLabs, Beverly, MA, USA Completely random NNK Linear The randomized peptide sequences in the library are expressed between the leader sequence and the mature N-terminus of the minor coat protein pIII, resulting in an average valency of 5 displayed peptides per virion. For the linear Ph.D.-12 libraries, the first position of the mature displayed fusion protein is the first randomized position. Each displayed peptide is followed by a short spacer (Gly-Gly-Gly-Ser) and then the wild-type pIII sequence. The display vector used for the library is a derivative of wild-type M13 phage-simple propagation of the library as phage rather than plasmid eliminates the need for antibiotic selection and a separate helper phage superinfection step, saving time and effort. Extensive sequencing of the library has revealed a wide diversity of side chains at each position with no obvious positional biases. 2 Ph.D.-7 phage display library (X7) 7 ~1.0e9 ~1.0e13 New England BioLabs, Beverly, MA, USA Completely random NNK Linear The randomized peptide sequences in the library are expressed between the leader sequence and the mature N-terminus of the minor coat protein pIII, resulting in an average valency of 5 displayed peptides per virion. For the linear Ph.D.-7 libraries, the first position of the mature displayed fusion protein is the first randomized position. Each displayed peptide is followed by a short spacer (Gly-Gly-Gly-Ser) and then the wild-type pIII sequence. The display vector used for the library is a derivative of wild-type M13 phage-simple propagation of the library as phage rather than plasmid eliminates the need for antibiotic selection and a separate helper phage superinfection step, saving time and effort. Extensive sequencing of the library has revealed a wide diversity of side chains at each position with no obvious positional biases. 3 Ph.D.-C7C phage display library (CX7C) 7 ~1.0e9 ~1.0e13 New England BioLabs, Beverly, MA, USA Completely random NNK Circular The randomized peptide sequences in the library are expressed between the leader sequence and the mature N-terminus of the minor coat protein pIII, resulting in an average valency of 5 displayed peptides per virion. For the Ph.D.-C7C disulfide-constrained library, the randomized sequence is preceded by Ala-Cys at the N-terminus. Each displayed peptide is followed by a short spacer (Gly-Gly-Gly-Ser) and then the wild-type pIII sequence. The display vector used for the library is a derivative of wild-type M13 phage-simple propagation of the library as phage rather than plasmid eliminates the need for antibiotic selection and a separate helper phage superinfection step, saving time and effort. Extensive sequencing of the library has revealed a wide diversity of side chains at each position with no obvious positional biases. 4 f3-6mer phage display library (X6) 6 2.0e8 G. Smith (University of Missouri, Columbia, MO) Completely random NNK Linear Library f3-6mer (GenBank Accession AF246446) is based on vector fUSE5, which displys its guest peptides on all five copies of the minor coat protein pIII at one tip of the virion. The library is also known as fUSE/6mer. 5 f3-15mer phage display library (X15) 15 2.5e8 G. Smith (University of Missouri, Columbia, MO) Completely random NNK Linear Library f3-15mer (GenBank Accession AF246445) is based on vector fUSE5, which displys its guest peptides on all five copies of the minor coat protein pIII at one tip of the virion. The library is also known as fUSE/15mer. 6 f88-15mer phage display library (X15) 15 2.0e9 G. Smith (University of Missouri, Columbia, MO) Completely random NNK Linear Library f88-15mer (GenBank Accession AF246448) is based on vector f88-4, which displays its guest peptides on 100 to 300 copies of the major coat protein pVIII. The library is also known as f88/15mer. 7 ACX7CG phage display library 7 2.3e8 Christian Heinis (Institute of Chemical Sciences and Engineering, Switzerland) Completely random NNK Circular The peptides containing seven random amino acids flanked on each side by cysteines were displayed as fusions with the minor coat protein pIII on filamentous phage. 8 f88-Cys1 phage display library (X5CXCX5) 13 2.8e9 G. Smith (University of Missouri, Columbia, MO) Semi-random NNK Circular Library f88-Cys1 (GenBank Accession AF246450) is based on vector f88-4, which displays its guest peptides on 100 to 300 copies of the major coat protein pVIII. The library is also known as Cys1. 9 f88-Cys2 phage display library (X5CX2CX5) 14 5.5e7 G. Smith (University of Missouri, Columbia, MO) Semi-random NNK Circular Library f88-Cys2 (GenBank Accession AF246451) is based on vector f88-4, which displays its guest peptides on 100 to 300 copies of the major coat protein pVIII. The library is also known as Cys2. 10 f88-Cys3 phage display library (X5CX3CX4) 14 5.2e7 G. Smith (University of Missouri, Columbia, MO) Semi-random NNK Circular Library f88-Cys3 (GenBank Accession AF246452) is based on vector f88-4, which displays its guest peptides on 100 to 300 copies of the major coat protein pVIII. The library is also known as Cys3. 11 f88-Cys4 phage display library (X4CX4CX5) 15 1.7e8 G. Smith (University of Missouri, Columbia, MO) Semi-random NNK Circular Library f88-Cys4 (GenBank Accession AF246453) is based on vector f88-4, which displays its guest peptides on 100 to 300 copies of the major coat protein pVIII. The library is also known as Cys4. 12 AXCX5CXG phage display library 9 1.05e7 Christian Heinis (Institute of Chemical Sciences and Engineering, Switzerland) Semi-random NNK Circular The peptides containing five random amino acids flanked on each side by cysteines were displayed as fusions with the minor coat protein pIII on filamentous phage. 13 f88-Cys6 phage display library (X4CX6CX4) 16 2.7e8 G. Smith (University of Missouri, Columbia, MO) Semi-random NNK Circular Library f88-Cys6 (GenBank Accession AF246454) is based on vector f88-4, which displays its guest peptides on 100 to 300 copies of the major coat protein pVIII. 14 f88-LX6 phage display library (XCX6CX) 10 1.0e10 J. K. Scott Semi-random NNM Circular f88-LX6 (GenBank accession number AF246456) were constructed in vector f88-4, which displays its guest peptides on 100 to 300 copies of the major coat protein pVIII. Met and Trp are absent from this library. 15 f8-8mer phage display library (X8) 8 2.0e9 V. A. Petrenko and G. P. Smith Completely random NNK Linear Library f8-8mer (GenBank accession number AF246447) was constructed in vector f8-1, which displays its guest peptides on all 3,900 copies of pVIII. In fact, codons of X8 is Gnk-(nnk)6-nnG. 16 CL6 phage display library (CX6C) 6 9.0e8 1.0e13 L. Mazzucchelli and J. B. Burritt Completely random NNK Linear CL6 was constructed using a vector M13KBstX, which has kanamycin resistance. 17 CL10 phage display library (CX10C) 10 1.04e19 1.0e13 L. Mazzucchelli and J. B. Burritt Completely random NNK Circular CL10 was constructed using a vector M13KBstX, which has kanamycin resistance. 18 LL9 phage display library (X9) 9 3.66e9 L. Mazzucchelli and J. B. Burritt Completely random Linear 19 J404 phage display library (X9) 9 L. Mazzucchelli and J. B. Burritt Completely random NNK Linear J404 is a linear random nonapeptide M13 phage display library with kanamycin resistance. 20 X6 fAFF1 phage display library 6 3.0e8 W. Dower (Affymax) Completely random NNK Linear The library is based on a filamentous bacteriophage affinity vector, fAFF1, which was constructed from the tetracycline resistance-transducing vector fd-tet. Random peptides were express on protein III. Coding scheme: NNK, where N represents equimolar A, C, G, or T and K is equimolar G or T. NH2-XXXXXXGG=TVESC, amino acids after the equals sign belong to the native gene III protein. 21 X12 fAFF1 phage display library 12 3.0e8 W. Dower (Affymax) Completely random NNK Linear The library is based on a filamentous bacteriophage affinity vector, fAFF1, which was constructed from the tetracycline resistance-transducing vector fd-tet. Random peptides were express on protein III. 22 X20 fAFF1 phage display library 20 4.0e8 W. Dower (Affymax) Completely random NNK Linear The library is based on a filamentous bacteriophage affinity vector, fAFF1, which was constructed from the tetracycline resistance-transducing vector fd-tet. Random peptides were express on protein III. 23 ON1203 phage display library (CX8C) 8 2.4e9 Affymax Completely random Circular The gene for pVIII was chemically synthesized with the use of four overlapping oligonucleotides. The gene was inserted into the Nhe and Hind IlIl sites of the phagemid vector pBAD18, placing the expression under the control of the araB promoter (plasmid p8V2). A cloning site consisting of two noncomplementary Bst Xl sites was included at the 5' end of the gene for pVIII and was used to clone collections of degenerate oligonucleotides by the half-site primer approach as described. Library ON1203 was constructed in this vector. 24 X6 fAFF1-tether C phage display library 6 2.0e8 Marc Navre (Affymax) Completely random NNK Linear This library is based on fAFF1 vector, displaying random hexapeptides linked to pIII. 25 X8, X10 and X12 phage display library pool 8, 10, 12 Affymax Completely random Linear Libraries of random peptides were expressed at the N terminus of fd phage pIII protein or on the N terminus of the fd phage major coat protein pVIII.