Development of new Raman optical activity techniques

Raman optical activity (ROA) has been developed over the past two decades as a technique to acquire stereochemical information. This dissertation represents improvements in experimental ROA measurements, previous formulations of ROA intensity theory, and measurement artifact theory. Among the conventional and newly developed ROA techniques presented in this dissertation, backward in-phase dual circular polarization (DCP\sb{\rm I}) is identified as the most favorable ROA measurement to study biological molecules in the nonresonant cases. The validity of the nonresonant approximation is investigated by comparing the ROA spectra of right-angle depolarized incident and scattered circular polarization (ICP and SCP), and backward DCP\sb{\rm I} and unpolarized ICP measurements. An experimental scheme for the complete isolation of ROA tensor invariants in the nonresonant limit is presented and is implemented for the isolation of anisotropic ROA invariants of trans-pinane and $\alpha$-pinene

Decoding Randomly Ordered DNA Arrays

We have developed a simple and efficient algorithm to identify each member of a large collection of DNA-linked objects through the use of hybridization, and have applied it to the manufacture of randomly assembled arrays of beads in wells. Once the algorithm has been used to determine the identity of each bead, the microarray can be used in a wide variety of applications, including single nucleotide polymorphism genotyping and gene expression profiling. The algorithm requires only a few labels and several sequential hybridizations to identify thousands of different DNA sequences with great accuracy. We have decoded tens of thousands of arrays, each with 1520 sequences represented at ∼30-fold redundancy by up to ∼50,000 beads, with a median error rate of <1 × 10(-4) per bead. The approach makes use of error checking codes and provides, for the first time, a direct functional quality control of every element of each array that is manufactured. The algorithm can be applied to any spatially fixed collection of objects or molecules that are associated with specific DNA sequences