Future Developments

There are numerous developments at all stages of genotyping. Examples include "genotype sorting" methods (microsphere sorting, Lynxgen) and also single molecule analysis of linear DNA strands (electromagnetic chips, U.S. Genomics).

The Lynxgen technology uses a library of approximately 16 million short synthetic DNA sequences, called "tags," and their complementary "antitags," to uniquely mark and process each DNA molecule in a sample. They are attached to 5 mm microbeads each of which carries multiple copies of a short antitag DNA sequence. The amplified tagged DNA molecules are then collected onto the microspheres through hybridization of the tags to the complementary antitags in a "a self-sorting process." Each microbead carries on its surface enough complementary antitags to collect approximately 100,000 identical copies of the corresponding tagged DNA molecule. Due to this process, each tagged DNA molecule in the original sample is converted into a microbead carrying about 100,000 copies of the same sequence. Therefore, in the complex mixture of a million or more identified DNA molecules substantially all the different DNA molecules present in a sample are represented in the final microbead collection, which can then be extracted, for example, by flow-cytometry methods.

A technology recently presented by U.S. Genomics relies on the direct and linear reading of large sections of single genomes. Linear analysis is powerful as there is no upper limit on the size of the DNA that is read. The biophysical rendering of the polymerase-DNA on an electromagnetic chip uses nanotechnology for positioning DNA and also fluorescent, electrical, and force-dependent detection technologies to allow for reading the sequence information.

These sophisticated techniques and instruments probably all require specialized instrumentation (1). Although a cutting-edge technology, many come still at a price too high for many laboratories. This may be overcome by the near future, either by further miniaturization ("lab-on-chip") or by commercial genotyping labs working in order and for account of academic laboratories. We will be facing a new era of studies involving the genotyping of thousands of SNPs every day, with an unprecedented number of samples wherein even genome-wide association studies will be possible. The planning and analysis of these studies will then cost more than the actual genotyping (7). Accurate genotyping and reporting, however, will always be a critical factor to find those associations ardently searched.

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Cure Your Yeast Infection For Good

The term vaginitis is one that is applied to any inflammation or infection of the vagina, and there are many different conditions that are categorized together under this ‘broad’ heading, including bacterial vaginosis, trichomoniasis and non-infectious vaginitis.

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