« Super Mario 64 | Main | This weekend, I... »
June 27, 2006
Poke, poke, slow!
Nowadays when friends and acquaintances asked me what i'm doing this summer, I'll say 'doing research'. Upon further querry about the field of research, I'll invariably say, 'dealing with chicks'. One reason I don't feel like elaborating is because no one will understand my exemplifications, except fellow friends who are majoring in biology (even most of them gave me the i-understand-a-little-but-heck-it's-too-compartmentalized-to-ask-further-questions look). Another reason is to give the benefit of the doubt to guys who might be defining 'chicks' the other way.
On the other hand, it's politically incorrect to say I'm dealing with yellow, fluffy chicks either. I cut the embryos long before they are born, ie. while still featherless they are 'mercifully' sacrificed (what an oxymoron). That sounds cruel right? Both to me and the still-born chicks.
Today I spent 7 hours just to section an E7 (embryonic day 7) embryo. 7 freaking hours! As it is relatively large and has more tissues to section through, not to mention that the orientation today is horizontal sectioning, which is totally different from the transverse sectioning that I am more familiar with, and hence it's totally impossible to recognize the inner ear structure on the sections. I have 12 slides to fill with sections containing not partial front or partial back, but the whole inner ear organ. So I was challenged with the almost impossible task to find the lagena macula (an area of the inner ear next to basilar papilla), the part which will reach the sectioning knife first. I was told by the post-graduate researcher I was heping that the part looked like a pin-prick hole surrounded by a layer of membrane the width of 50 microns (!). Imagine each section is 0.5cm X 1cm X 10 microns; simple math will tell you that the membrane occupies only 0.001% of the volume!
It's a pain in the neck (literally) just to search the membrane to make sure that i won't miss saving any part of the inner ear. After what it seems like eternity of sectioning, searching for the membrane under the microscope and repeating the sequences again, I finally reached the membrane and saved exactly 144 sections of the inner ear on 12 slides (12 sections per slide). At least now i know that an E7 chick embryo has inner ear of about 1.44mm long. That's even less than the thinkness of a 10 sen coin OMG! E4 embryos have about 1mm long inner ears; Gauging both information and the difference in the E4 inner ear structure and E7 inner ear structure, I can surmise that the growth of chick inner ear in 3 days comprises structural morphology as well as cell specialization into auditory and vestibular areas.
But that is not the gist of my experiment (If you still can follow my writings). I am investigating the role of Slits and Robos in axon guidance of the chik inner ear (now you see why i don't like to explain what i'm researching about). The integral method I'm using to do that is through in situ hybridization (ISH), which is a lengthy 3-day procedure to bind the molecules intended for investigation (in this case, the Slits and the Robos) with RNA probes which, with BM purple treatment, show bluish color on parts of the inner ear where the Slits/Robos are expressed. I had the first run of the procedure last week with promising results. Ah, the sweetness of reaping fruits of extensive labor!
Still, I don't like sectioning embryos coz i'm slow at it. Slow as a slowpoke. S-L-O-W. Slow.
Posted by peixin at June 27, 2006 06:59 AM
Comments
@@
Posted by: ls at June 27, 2006 02:29 PM
lol, you're really in deep. :P
Don't worry, your writings are still quite understandable for the most part (relatively speaking). But do remember that we laypeople do not know what exactly are slits/robos? There's Google, but I'd think that we'd rather have you to explain than having to wade through PubMed!
Oh, slow and steady does it. You wouldn't want to ruin it and have to do it all over again! That'll really screw your day. Cheers!
Posted by: hm at June 28, 2006 12:11 AM