Library maximum randomness

The probability that a sequence of interest is present in a library can be calculated as shown in Table 10.1. The optimal digestion of the target (e.g., partial digest with SamSA) to obtain maximum randomness of cloning is achieved when the most abundant insert size equals the vector capacity (Seed et al., 1982). A problem which may frequently occur is the change of representation of clones in the libraries during amplification. Some clones may be lost or become under-represented just because they reproduce slightly less rapidly. Independent libraries may then have to be screened. False positives also occur often, even if utmost care is taken to prevent contamination. 

The container was designed to hold between 5-10 books In any desired orientation. The size was Initially based on a random selection of books taken from the Humanities and Social Science collections of the British Library. The container was built to withstand the calculated maximum and minimum pressure changes which were likely to occur during processing. Monomer Introduction into the container took place under ambient conditions and several different procedures were developed and tested. 

To test these possibilities, random segments of four to seven residues were inserted into the middle of the EcCM HI helix [95]. The individual libraries (designated L4, L5, L6 and L7) have a maximum theoretical diversity of 160,000 (204), 3.2 x 106 (205), 6.4 x 107 (206), and 1.28 x 109 (207) distinct members, respectively. In each case, transformation of chorismate mutase-deficient bacteria yielded roughly 107 clones, giving fully diverse and redundant coverage of the L4 and L5 libraries, 10 % sequence coverage of the L6 library, and 1 % coverage of the L7 library. 

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