Three different levels of resolution for HLA typing are usually recognized (Table 1). Low-resolution typing, also referred to as generic typing or two-digit typing, corresponds to the identification of broad families of alleles that cluster into serotypes (e.g., A*02), and is the equivalent of serological typing (A2). High-resolution typing (four-digit typing) allows the discrimination of individual alleles within each serotype (e.g., A*0201). Intermediate resolution provides information on a limited number of alleles that could be present in a given individual, excluding all other known alleles. In clinical transplantation setting, low-resolution HLA typing is required for solidorgan transplant programs, whereas high-resolution typing is required for HSC transplantation, particularly for unrelated donor matching.[3,4] For HLA-disease association studies, some diseases require low-resolution typing
In the early age of molecular typing, restriction fragment length polymorphism (RFLP) allowed to discriminate not only the serotypes, but also some groups of alleles subdividing serotypes, particularly for DRB and DQA1/ DQB1 loci. However, most polymorphic restriction sites were located in noncoding regions and the technique, although very useful in the late 1980s, was not resolutive enough to cope with the continuously growing HLA allelic polymorphism and was too cumbersome for routine clinical use.
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The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.