ABSTRACT
This chapter outlines many methods used in nucleic acid based diagnosis. Hybridization detection methods rely on the specificity of base pairing, and also on the fact that mismatched sequences that bind have a different melting temperature compared to those which are correctly matched. To be visualized, the probes have to labeled in some way. These labeled molecules can be used in in situ hybridization techniques. For small DNA fragment separation, polyacrylamide gels are used instead of agarose. The commonest way to examine chromosomes is to look in metaphase, when the chromosomes are condensed, although there are now methods for interphase analysis. The area where technology will have the greatest impact will be the use of silicon chips as the matrix for oligonucleotide probes that detect mutations.
