Common Mistakes

Common Mistakes

DNA Technology

DNA will migrate to the positive electrode due to its negatively charged backbone. This is usually the red colored electrode, so remember, "run to red."

Electro this, electro that, electro what? Both electrophoresis and electroporation use electricity or a current to do their jobs. Electrophoresis separates nucleic acids based on size and charge and electroporation creates pores so DNA can enter a cell.

Gene Expression

With the compass naming system, it's easy to forget exactly what a Southern, Northern and Western blot actually look for and how you would choose which technique to use. Just remember this: Sally Donned Nancy's Meticulous White Pants (Southern = DNA, Northern = mRNA, Western = protein).

Gene Function

You might think that only the anti-sense is necessary for RNA interference, but, in fact, the buddy system is strictly enforced in RNAi. Double-stranded siRNA is essential for RNAi to occur.

Organism Cloning

Differentiated or dedifferentiated? Struggling to understand these terms that sound so much alike? Remember that in order to become dedifferentiated, cells have to be differentiated first. The prefix "de-" means something has been taken away.

Forensic Applications

Forensic scientists do not actually look at the differences in the sequence of nucleotides between the DNA left at a crime scene and the suspects. They analyze the number of repeats of small DNA sequences.

Medical Applications

Genes cannot be delivered to human cells alone in gene therapy. They first have to be cloned into an efficient vehicle first. We're not talking about a Toyota Prius here, but a viral vector that can deliver the gene to the target cells and incorporate the gene into their genome.

GM Foods

Cloning genes and inserting them into an organism isn't the only way to modify an organism's genes. For instance, seedless watermelons are produced by manipulating the genome chemically. Seeds are treated with a chemical that causes the chromosomes to double, forming a tetraploid plant. Then the plant is pollinated with a diploid normal plant, resulting in triploid offspring. Triploid watermelons produce sterile offspring without seeds.