| SSB | short spike burst; sicca syndrome B; single-strand break; single-stranded binding [protein]; stereos... |
|---|---|
| ss(c)DNA | single-stranded circular deoxyribonucleic acid |
| SSCP | single-stranded conformational polymorphism |
| ssDNA | single-stranded DNA |
| ssRNA | single-stranded ribonucleic acid |
| negative lens | <physics> A lens with a negative focal length. The edge of a negative lens is thicker than the centre. The three negative lenses are, according to their figure: planoconcave, double concave or biconcave, and diverging concavoconvex or diverging meniscus. See: lens, simple. (05 Aug 1998) |
|---|---|
| negative meniscus | A convexoconcave lens in which the power of the concavity exceeds that of the convexity. Synonym: negative meniscus. (05 Mar 2000) |
| negative phase | The period during which the opsonic index is lowered following the injection of a vaccine. (05 Mar 2000) |
| negative pressure | Pressure less than that of the ambient atmosphere. (05 Mar 2000) |
| negative regulation | Negative feedback in biological systems mediated by allosteric regulatory enzymes. (18 Nov 1997) |
| negative S | Characteristic sedimentation behaviour of a lipoprotein fraction of plasma in a centrifugal field in a medium of appropriate density, achieved by adding a salt or D2O to the plasma. Synonym: negative S, Svedberg of flotation. (05 Mar 2000) |
| negative scotoma | A scotoma that is not ordinarily perceived, but is detected only on examination of the visual field. (05 Mar 2000) |
| negative stain | <technique> Stain forming an opaque or coloured background against which the object to be demonstrated appears as a translucent or colourless area; in electron microscopy, an electron opaque material, such as phosphotungstic acid or sodium phosphotungstate, is used to give detail as to surface structure. (05 Mar 2000) |
| negative staining | Microscopic technique in which the object stands out against a dark background of stain. For electron microscopy the sample is suspended in a solution of an electron dense stain such as sodium phosphotungstate and then sprayed onto a support grid. The stain dries as structureless solid and fills all crevices in the sample. When examined in the electron microscope the sample appears as a light object against a dark background. Quite fine structural detail can be observed using negative staining and it has been used extensively to study the structure of viruses and other particulate samples. (18 Nov 1997) |
| negative taxis | The repulsion of protoplasm away from a stimulus. (05 Mar 2000) |
| negative thermotaxis | Repulsion of a plant or animal from heat. (05 Mar 2000) |
| negative transference | Transference characterised by predominantly hostile feelings on the part of the patient toward the analyst. (05 Mar 2000) |
| eyepiece, negative | <microscopy> An ocular in which the real image of the object is formed between two lenses. The Huygens type. (05 Aug 1998) |
| false negative | <statistics> A term used to indicate a test showed an incorrect negative result. (16 Dec 1997) |
| false-negative reaction | <statistics> An erroneous or mistakenly negative response. Negative test results in subjects who possess the attribute for which the test is conducted. The labeling of diseased persons as healthy when screening in the detection of disease. (05 Mar 2000) |