Abstract: Two basic design criteria for producing oligonucleotide "negative control probes" for use in nucleic acid hybridization assays are described. Each type of negative control probe also functions as a synthetic polynucleotide "target" that is useful for testing the other type of negative control probe. These design criteria also provide structures that are not naturally occurring, but are analogous to naturally occurring nucleic acids in primary, secondary and tertiary structure. These design criteria are useful in hybridization assays and potentially in other applications as well.

Abstract: Oligonucleotide probes complementary to the 16S rRNA molecule, suitably labelled, that bind to a characteristic portion of the 16S rRNA molecule of spore-forming sulfate reducing bacterial (SRB) and/or the non-spore forming SRB, Desulfovibrio desulfuricans, are described. The use of these probes in conjunction with "negative control probes" to detect these bacteria in the oilfield as well as any other environment in qualitative and quantitative assays is described. Use of "Universal C" primer as a probe to detect all bacteria for total bacterial assays in environmental samples is described.