This paper describes the development and evaluation of in situ hybridization (ISH) for the detection of rhinovirus in cells obtained from nasal washings of volunteers infected with human rhinovirus 14 (HRV-14). Twenty-five (66%) and 27 (71%) of 38 volunteers inoculated with HRV-14 had evidence of infection by virus isolation and ISH, respectively, on at least one of 4 days investigated after virus challenge. In contrast, only 14 of 38 (37%) volunteers had significant antibody rises as detected by the neutralization test. Of the 38 volunteers inoculated with HRV-14, only 13 (34%) had symptoms of colds. Of these, 12 (92%) and 10 (77%) were positive by virus isolation or ISH, respectively, on at least one day. Six (46%) had significant antibody rises by neutralization. Similarly, of the 38 volunteers challenged, 22 (58%) were asymptomatic and of these 10 (45.5%) and 12 (54.5%) were positive by virus isolation and ISH, respectively, on at least one day. Only 8 (36.4%) of these asymptomatic volunteers showed significant antibody rises by neutralization. There were significant associations between the detection of rhinoviruses by ISH and virus isolation on the third day (P less than 0.025) after virus challenge in the group as a whole and in the symptomatic group. These results show that generally rhinovirus detection by ISH compares well with virus isolation and both tests are clearly more sensitive than the neutralization test in detecting evidence of infection. It is concluded that ISH is an interesting new technique that may play an important role in the study of rhinovirus infection and pathogenesis.

Non-radioactive techniques can be applied to many in situ hybridization (ISH) applications, and a number of non-radioactive labels for this process have been reported. However, these labels have some inherent problems in terms of both background and signal-to-noise values. We have sought to address these issues by searching for an alternative label that has the following features: efficient incorporation into probes, non-endogenous to biological systems, the availability of a high-affinity, high-specificity antibody. Fluorescein has been shown to meet these requirements. In addition, due to the fluorescent nature of the label, it has been possible to design a rapid, non-radioactive labelling assay and also to view in situ hybridization results by direct fluorescence in certain ISH applications. The hybridization kinetics have been investigated. Significant improvements have been made to the hybridization buffer leading to reduced background and increased rates of hybridization when compared to traditional hybridization buffers.

The labeling of oligonucleotide probes using a fluorescein-labeled nucleotide is described. The reaction is characterized by careful control of the nucleotide and probe molar ratio in order to produce a tail that gives good detection sensitivity without compromising hybridization stringency control of the probe sequence. The labeling reaction can be easily monitored for incorporation of the fluorescent label and the probes can be used in many applications.

This study investigated the abilities of cDNA probes from the 5' and 3' ends of the genome of human rhinoviruses (HRV-) 14, 9, and 1B to detect RNA from 59 rhinovirus serotypes. The results show that probes from the 5' end of the genomes of HRV-14, 9, and 1 B detected a large number of serotypes but the detection rate was variable and depended on the degree of homology with the particular probe. In contrast, all the 3' end probes were specific for the homologous virus. However, a long HRV-9 probe detected a large number of serotypes. It was concluded that such cDNA probes would not detect all serotypes with equal efficiency. Synthetic oligonucleotides corresponding to short but highly conserved regions in the 5' non coding region may overcome this problem.

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