background and aims: viroids are smallest known plant pathogens and cause several economically significant diseases. until recently, viroid detection relied mainly on biological tests and indexing. today various diagnostic techniques such as nucleic acid hybridization, southern blot and reverse transcription coupled with polymerase chain reaction (rt-pcr) are being used for detection and diagno...

Background and Aims: Viroids are smallest known plant pathogens and cause several economically significant diseases. Until recently, viroid detection relied mainly on biological tests and indexing. Today various diagnostic techniques such as nucleic acid hybridization, southern blot and reverse transcription coupled with polymerase chain reaction (RT-PCR) are being used for detection and diag...

The umuDC operon of Escherichia coli is required for efficient mutagenesis by UV light and many other DNA-damaging agents. The existence of a umuDC analog in Salmonella typhimurium has been questioned. With DNA probes to the E. coli umuD and umuC genes, we detected, by Southern blot hybridization, sequences similar to both of these genes in S. typhimurium LT2. We also confirmed that the presenc...

Specimens from 26 condylomatous lesions, 24 invasive cancer cells, and 33 cervices, without evidence of the diseases, were tested for the presence of human papillomavirus (HPV) types 6, 11, 16, and 18 by Southern blot hybridization, in situ filter hybridization, or in situ tissue hybridization methods. A total of 89% (23 of 26) of the condylomatous lesions contained HPV DNAs, as determined by o...

Simian acquired immune deficiency syndrome (SAIDS) in rhesus macaques (Macaca mulatta) at the California Primate Research Center is caused by a type D retrovirus designated SAIDS retrovirus serotype 1 (SRV-1). This syndrome is characterized by profound immunosuppression and death associated with opportunistic infections. Neurologic signs and lesions have not been described as part of this syndr...

The molecular structure of the exceptional telomeres of six plant species belonging to the order Asparagales and two species of the order Liliales was analyzed using Southern blot and fluorescence in situ hybridization. Three different situations were found, namely: i) In the two Liliales species, Tulipa australis (Liliaceae) and Merendera montana (Colchicaceae), the chromosome ends display hyb...