Thursday, December 08, 2005

Microinjecting my brains out ...

I've been microinjecting cells like a madman recently (or perhaps a mad scientist?)

Microinjection is a very useful technique - you can basically shove anything into a cell. Antibodies, DNA, RNA, quantum-dots ...

One question that fellow scientists ask me is whether microinjection damages cells in anyway. You would be surprised how resilient cells are. As far as we know microinjected cells display normal functions. They can transcribe DNA into RNA. They can translate the RNA into protein. They can migrate. In the case of neurons, they can form axons.

One of the classic microinjection papers is Yuli Wang's microinjection of fluorescent actin, a component of the cytoskeleton. Another was Tim Mitchison's injection of fluorescent tubulin, another cytoskeletal component. Both papers led to major discoveries as it allowed the researchers to monitor how cells and molecules change over time. In cells the cytoskeleton could be remodled and reorganized in minutes - it's a dynamic rather than than a solid scafold for the cell. Visualizing molecules inside of living cells was a big deal as the behavior of biological molecules over time - the illusive dimension - could now be analyzed.

Ok I've got another time-point to take care of ...

Refs:

Taylor DL, Wang YL. Molecular cytochemistry: incorporation of fluorescently labeled actin into living cells.
Proc Natl Acad Sci U S A. 1978 Feb;75(2):857-61.

Mitchison T, Kirschner M. Dynamic instability of microtubule growth.
Nature. 1984 Nov 15-21;312(5991):237-42.