Term
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Definition
-determine HIV status and prevent transmission
-20,000 new infections per year due to not knowing HIV+
-getting proper treatment and care - depends of viral load of patient and progression
-100 million HIV tests per year |
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Term
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Definition
-probability of a negative test when serum lacks anti-HIV AB
-only detect anti-HIV AB and not viruses
-no false positives |
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Term
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Definition
-probability of a positive test when serum contains anti-HIV AB
-detects very low amount of AB in serum
-no false negatives |
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Term
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Definition
Enzyme-linked immunosorbent assay
1. Direct measures concentration of HIV particles
2. Indirect measures concentration of AB |
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Term
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Definition
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Term
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Definition
-performed after all positive ELISA tests (to confirm)
-more laborious and costly
-more sensitive but less specific |
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Term
| Western Blot Analysis Process |
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Definition
1. purify HIV with SDS (sodium dodecyl sulfate) and detergent to lyse cells and inactivate HIV
2. resolve HIV particles based on size (molecular weight) with Polyachrylamine Gel Electrophoresis (SDS PAGE)
-proteins lowered into well of gel submerged in buffer
-electrical current applied (negative proteins move toward cathode +)
-proteins move through gel pores and are arranged by size
3. Proteins transferred from gel to membrane (electrophoretically)
4. Seven major HIV protein resolved
-P24 (capsid) and GP41-45 = diagnostic proteins
5. then same as ELISA to determine binding and presence of anti-HIV AB |
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Term
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Definition
-detect HIV RNA
1. plasma sample from patient - heat to lyse and release ssRNA
2. Precipitate RNA with isopropanol and remove debris
3. Add reverse transcriptase: ss RNA -> ss cDNA -(DNA polymerase)> ds cDNA
4. PCR (Polymerase Chain Reaction) to multiply specific gag gene and make millions of copies
5. gag gene copies are bound to membrane
6. ds gag genes are denatured to ss gag genes
7. a radioactive or fluorescently tagged gene probe is added and it binds via complementarity to a portion of gag gene
8. wash away unbound robe
9. measure radioactivity or fluorescence
10. quantifies # HIV/ml plasma
=viral load |
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Term
| Quantifying Viral Load Characteristics |
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Definition
-very specific and sensitive
-can measure 40 RNA copies/ml (detection load) |
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Term
| Determine CD4 cell Count in blood |
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Definition
-do you have AIDS?
-when do you need treatment?
-make antibodies against all types of CD4 cells with specific fluorescent dyes (light up under UV light)
-to count different types of cells: FACS (fluorescently activated cell sorter) - use laser beam to excite dyes and electrical field to sort cells |
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