Question

Which of the following is a critically important tool used in experiments involving DNA hybridisation?
A. DNA sequencing machines
B. Ligases
C. DNA probes
D. Vectors

Answer 1

Hint: DNA hybridisation offers an extremely powerful tool in molecular biology. Hybridisation allows the identification and cloning of certain genes, analysis of the copy number of sequences in the genome, analysis of levels of mRNA in cells, and DNA fingerprinting, among other applications.

Complete Step-by-step answer:

DNA probes is a fragment of DNA containing a nucleotide sequence specifically for the gene or chromosomal region of interest. DNA probes use nucleic acid hybridisation with specially built sequences that are complementary to the target sequence in the sample being tested. The probes bond (hybridise) with the target sequence wherever it appears in the DNA sample. DNA probes are generally labelled, for instance with epitopes, radioisotopes, biotin, or fluorophores in order to activate their detection.
A DNA sequencer is a scientific tool used to automate the DNA sequencing process. Some DNA sequencers can be also considered optical instruments as they analyse light signals that originate from fluorochromes affixed to the nucleotides.
Ligase is an enzyme that catalyses the binding of two molecules. One example is DNA ligase which connects two fragments of DNA by developing a phosphodiester bond.
A vector is a living organism that transmits an infectious agent from an infected animal to a human or another animal. Vectors are often arthropods, like fleas, flies, ticks, mosquitoes, and lice.
Therefore the correct answer is Option C.

Note: A probe is a labeled single strand of RNA or DNA utilised in order to find its complementary sequence. Probes are often used in Northern and Southern blots, and in library screening. Thus, probes can be utilised for two kinds of methods, hybridisation reactions, and qPCR.