What will happen if foreign DNA is injected into human?

We see hollywood flicks where we find transgenic monster in all forms,can we do that in real life as well.Can we make that happen in a laboratory ?

Let;'s say we want to create a mystical beast hybrid of tiger and human.So basically we need the DNA of a tiger to embed the quality of tiger into human.So we take out the DNA of tiger and inject it to human,so what will happen next are we going to get the stripes of tiger ,or the bloody claws??

Fact is nothing will happen, if the injection is not pure the most spectacular thing may be an immune response, and the extreme case an anaphylactic shock (and death).

Free floating DNA molecules in the blood stream are common, if they are somehow delivered inside the cell they would either cause the cell to die or recognized as foreign DNA and removed. In the intercellular space or blood I suspect that macrophages (type of immune cell) will eat all the tiger DNA

If you injected naked DNA from any species, nothing would really happen. The DNA would get degraded by cells of the immune system. If you injected a viral vector that infects human cells, and the viral vector carried a specific tiger gene, then the effects would depend on the viral vector and the gene, as well as which cells were targeted by the virus and incorporated the tiger gene. Even in this "gene therapy" or gene transduction scenario, not much would happen, as gene transduction has not been very successful and is not very easy to do in general, especially in humans. We can make transgenic mice carrying human DNA as models of some human diseases but then again the effects are limited to the specific gene in question. The mouse is still a mouse. If we made transgenic mice with a tiger gene, they would still be mice, behave like mice, etc.

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Unknown Wednesday, May 07, 2014  No comment

How to measure quality and quantity of DNA while doing experiments.?

One  can run your DNA sample on agarose gel to see, whether you have significant degradation.

If you are interested in contamination, you can make a standard photometric analysis to assess the 260/280 and 260/230 ratios and absorbance at 320 nm on NanoDrop or even something similar to Eppendorf's BioPhotometer.

BioPhotometer 

In case RNA may be an obstacle for some down-stream procedures, with Qubit one  can also measure separately DNA and RNA concentrations and then decide if you have too much RNA and it's worth treating your sample with RNase.

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Unknown Wednesday, April 02, 2014  No comment

Genetic:Recombination map and Physical Map

1) Why are both recombination maps and physical maps important? What are the differences between them?

2) When does crossing over occur?

3) What kind of recombination frequency is diagnostic for linkage?

4) Why do we make test crosses for mapping with the double recessive line?

5) How do we measure ‘distance’ when we map?

Are distances relative or absolute?

1--recombination map is the linkage map it can only be constructed for loci that occur in two or more heritable forms

physical map can be made from direct DNA analysis both are important as we try to correlate for acurate test and result

2--Crossing over takes place at hotspot site where there is high degree of complementarity

3--If the genes were independent, using standard genetic techniques you would predict that your offspring would have the phenotypic ratio,this would help in linkage,

Linkage analysis can be used to diagnostics linkage

4--For detecting linkage we do double recessive lines

5--- linkage map unit (LMU) these are relative as it can vary with Frequency of crossover (and thus of recombination) can be affected by location (crossing over is repressed close to the centromere) and proximity to another corssover.

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Unknown Monday, December 23, 2013  No comment