Towards a full karyotype screening of interphase cells: 'FISH and chip' technology

Numerical chromosome aberrations are incompatible with normal human develop ment. Our laboratories develop hybridization-based screening tools that gen erate a maximum or cytogenetic information for each polar body or blastomer e analyzed. The methods are developed considering that the abnormality migh t require preparation of case-specific probes and that only one or two cell s will be available for diagnosis, most of which might be in the interphase stage. Furthermore, assay efficiencies have to be high, since there is typ ically not enough time to repeat an experiment or reconfirm a result prior to fertilization or embryo transfer. Structural alterations are delineated with break point-spanning probes. When screening for numerical abnormalitie s, we apply a Spectral Imaging-based approach to simultaneously score as ma ny as ten different chromosome types in individual interphase cells. Finall y. DNA micro-arrays are under development to score all of the human chromos omes in a single experiment and to increase the resolution with which micro -deletions can be delineated. (C) 2001 Elsevier Science Ireland Ltd. All ri ghts reserved.