This change significantly increased the usage of probing techniques as fluorescent labeled probes are safer. Oligonucleotide microarrays are designed using pairs of oligonucleotide hybridization probes targeting CpG sites of interest. Newer tests identify GABHS serotypes using nucleic acid (DNA) probes or polymerase chain reaction. Images can be produced from a variety of methods including&colon; microscopy, imaging probes, and spectroscopy. The site was initially found with metal detectors and by using metal rods as probes. This is the principle applied in compensated oscilloscope probes to increase measurement bandwidth. RTG have been proposed for use on realistic interstellar precursor missions and interstellar probes. This allows the use of standard oscilloscope probes. Intraoperative ultrasound may be used to help guide placement of the freezing probes. Early flyby probes (Mariner 4) and later orbiters used radio occultation to perform aeronomy. PCR with the use of allele specific probes. There were many scientific findings about Venus from the data retrieved by the Venera probes. Attempts to signal, attract, or activate hypothetical Bracewell probes in Earth's vicinity have not succeeded. Quantum dot probes exhibit in vivo toxicity. Dione was first imaged by the "Voyager" space probes.