WEEK 1
This summer I have been given the
opportunity to spend 8 weeks working in the Griffin Lab at the University of
Kent working on Pig IVF and embryo sexing thanks to the Biochemical Society
summer studentship (woohoooo science!). After already spending last summer here
as a volunteer I have the advantage of knowing everyone (I'm part of the furniture) which got rid of some of the nerves.
However, since last time I was here I was working on a different project, I
have absolutely no idea what I am doing! The first job of all was to get
reading! I was given a pile of relevant research papers and I spent a good
amount of time highlighting and asking loads of ridiculous questions. For the
first week I have been focused on getting to grips with the pig IVP protocol
which involves a vast amount of pipetting, a huge amount of waiting and then
(the fun bit) using the micromanipulator!
After a couple of days delay the pig
ovaries finally arrived, albeit slightly too warm for comfort at a toasty 39˚C
(they should be a few degrees less after their little journey- probably a bit
hot going in!). Opening the flask released the stench of pig juice that soon
filled the room (I could even smell it through my cold!). After a bit of
getting used to the smell, the ovaries were taken out and an aspirator was used
to extract the oocytes from the follicles. Only the larger, juicy follicles
were pierced and the dark, nasty looking ones were left where they were. Some
of the warm handling medium needed to be aspirated regularly to maintain the
warm environment for the removed oocytes. The handling medium and oocytes were
then poured onto a pre-warmed petri dish and, using a really cool EZ grip
pipette with a bendy needle on the end, about 200 good oocytes (with 2/3 layers
of compact cumulous cells) were moved to a nunc plate. Porcine oocytes differ
from human oocytes in that they are much darker and thicker in appearance. These
cells were then transferred to a maturation plate containing some hormones,
along with some other bits and bobs, and placed in a CO2 controlled incubator
until the next day.
Evi (Masters) being a scientist and some cute piggies!
The next few steps involved some moving of
media and oocytes into different incubators but, seeing as this was quick to be
done, I got to spend the rest of the afternoon on the micromanipulator! Just
for a bit of practise, I spent some time figuring out the different
contraptions such as the fine and coarse controls as well as the micro tool
holders and then played around sucking dead pig oocytes into the holding
pipette, moving things around with the biopsy pipette and making holes in the
zona pellucida(s/ae?) with the laser (which had a fantastic huge red “FIRE”
button on the remote). The coarse controls let you move the micro tools further
across the field of view than the fine controls, which are used for the fiddly
bits. I tried my hand at then sucking out the cytoplasm of some of the cells
(pretending that I was extracting a blastocyst) by pushing the biopsy pipette
through the hole created by the laser and then using the suction control to
pull out the contents of the cell. This was really tricky because of the
rubbery texture of the cells and it took a few stabs with the pipette and a
couple of extra laser blasts to break through. My supervisor, Kate, is going
for a lecturer interview tomorrow so we all spent a bit of time in the
afternoon quizzing her and making her practise her presentation!
Micromanipularator
Fertilisation day arrived! Yet to see how
this has panned out but the sperm motility was pretty poor (they were mostly
dead or just having a little wiggle on the spot). Lots of testing of the media
had to be done to ensure good pH and osmolarity levels. After a small mishap
with a slight pH overshoot after adding too much NaOH all was forgiven and both
levels were on track for success! The only other issue was a slight spill of
half of the sperm wash stash (it was definitely one of those days) but we
luckily still had enough for what we needed to do! One of my favourite aspects
of today’s protocol was that you had to give the sperm their morning fix of
caffeine so that they would get a bit of a move on, you
can do it boys! And also…Kate got her job, YEYYYY!
Kate being happy about her new job!
Next week: PCR, FISH and more Piggiessssss!
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