ABSTRACT
Many aspects of molecular genetics necessitate the detection of nucleic acid sequences. Current approaches involving target amplification (in situ PCR, Primed in situ Labeling, Self-Sustained Sequence Replication, Strand Displacement Amplification), probe amplification (Ligase Chain Reaction, Padlock Probes, Rolling Circle Amplification) and signal amplification (Tyramide Signal Amplification, Branched DNA Amplification) are summarized in the present review, together with their advantages and limitations.
Subject(s)
Nucleic Acids/analysis , DNA Probes , Humans , Nucleic Acid Amplification TechniquesABSTRACT
This paper presents a preparative and staining procedure for plant mitotic chromosomes that uses a combination of PI (propidium iodide) and DAPI (4',6-diamidino-2-phenylindol) and which reveals a pattern of high-affinity regions for these fluorochromes. Nucleolar organiser regions (NORs), telomeres and centromeric regions exhibit high PI affinity (red), whereas other chromosomal regions exhibit high affinity for either PI (red) or DAPI (blue). NOR-bearing and other chromosomes are readily distinguished, facilitating karyotyping. The dual staining pattern was observed in all the plants tested. Aspects of NOR size, number and occurrence are discussed. A karyotype of rice metaphase chromosomes is presented, based on their fluorescent banding patterns.
Subject(s)
Fluorescent Dyes/pharmacology , Genetic Techniques , Indicators and Reagents/pharmacology , Indoles/pharmacology , Propidium/pharmacology , Centromere/ultrastructure , Chromosome Banding , Chromosomes , Karyotyping , Mitosis , Nucleolus Organizer Region/ultrastructure , Oryza/genetics , Plants/genetics , Telomere/ultrastructureABSTRACT
A preparation technique has been developed for plants with small chromosomes, which produces large numbers of good-quality mitotic preparations. The technique employs a hydrochloric acid treatment to hydrolyse the cytoplasm, facilitating the subsequent removal of cytoplasmic debris. The evaporative force of a methanol-based fixative is exploited to disperse the cytoplasm and to deposit the chromosomes in a single optical plane. This technique permits detailed observations of chromosome morphology and karyotyping. The mitotic preparations are also suitable for the complex analysis associated with in-situ hybridization, as in studies of genome interaction in plant hybrids.
