Enhanced sequencing by hybridization using pools of probes
The invention provides methods for sequencing by hybridization (SBH) using pools of probes that allow greater efficiency in conducting SBH by reducing the number of separate measurements of hybridization signals required to identify each particular nucleotide in a target nucleic acid sequence. The invention also provides pools and sets of pools of probes, as well as methods of generating pools of probes.
1. A set of pools of probes wherein each probe comprises an information region, wherein said set of probes includes a number of individual probes that is sufficient to determine the sequence of an unknown target nucleic acid by overlapping sequences of the information region of two or more of said probes that hybridize to said target nucleic acid, and wherein at least one pool comprises two or more probes having different sequences in the information regions and having the same label or no label, and wherein the set of the pools of probes also satisfies one or more of the following rules describing the information regions of the probes, said rules selected from the group consisting of:
a. a consensus sequence of at least one pool in the set consists only of the letters selected from the group consisting of V, H, D, B, and N;
b. a consensus sequence of probes in each pool in the set comprises more than three different letters selected from the group consisting of A, C, G, T, U, M, R, W, S, Y, K, V, H, D, B, and N;
c. consensus sequences from each informative position of all pools in the set comprise more than eight letters selected from the group consisting of A, C, G, T, U, M, R, W, S, Y, K, V, H, D, B, and N; and
d. consensus sequences from each information region of all pools in the set comprise more than five different letters selected from the group consisting of A, C, G, T, U, M, R, W, S, Y, K, V, H, D, B, and N, wherein at least one letter is selected from the group consisting of M, R, W, S, Y, and K.
2. The set of pools of probes of claim 1 wherein said set comprises all possible probes of the same length K, where K is greater than 3.
3. The set of pools of probes of claim 1 wherein each pool comprises more than 16 different probes.
4. The set of pools of probes of claim 3 wherein each pool comprises at least 32 different probes.
5. The set of pools of probes of claim 1 in which the pools are arranged in a spatially-addressable array, and wherein each pool has an address.
6. The set of pools of probes of claim 1 wherein at least two pools are mixed, wherein any two pools that are mixed are associated with different labels, and wherein all probes in a single pool are associated with the same label.