Direct labelling of BAC-DNA by rolling-circle amplification

Area of Science:

• Molecular Biology
• Genetics
• Biotechnology

Background:

• Efficient probe amplification and labeling are essential for sequence detection using fluorescent in situ hybridization (FISH).
• Chromosome painting via FISH requires substantial probe quantities derived from extended DNA templates.
• Nick translation is a common probe labeling method involving modified nucleotide incorporation.

Purpose of the Study:

• To demonstrate the successful application of rolling-circle amplification (RCA) for amplifying low amounts of long circular DNA templates.
• To show that RCA amplicons are suitable for nick translation labeling and subsequent FISH analysis.
• To present a novel, cost-effective method for simultaneous amplification and labeling of DNA probes using RCA.

Main Methods:

• Rolling-circle amplification (RCA) of single or pooled bacterial artificial chromosomes (BACs).
• Labeling of RCA amplicons using nick translation.
• Application of labeled probes in fluorescent in situ hybridization (FISH) for chromosome analysis.

Main Results:

• Successful amplification of very low amounts of long circular DNA templates (BACs or BAC pools) using RCA.
• RCA-generated amplicons were effectively labeled via nick translation.
• Demonstrated suitability of RCA-amplified and labeled probes for FISH, including chromosome painting.

Conclusions:

• RCA is a highly effective method for amplifying DNA probes from minimal starting material.
• RCA enables simultaneous amplification and labeling of probes in a cost- and labor-efficient manner.
• This optimized RCA approach facilitates advanced FISH applications like chromosome painting.