|
|
|
| Alison
presented today’s science seminar, the third in the series so
far, regarding the microgenetic components of the research being
conducted on the Pompeii worm (Alvinella).
|
|
|
| Birds
always start to gather in the sky when the sub is at the surface
(pre-descent and post-ascent). |
|
|
|
One piece of $50,000 equipment is on loan from Axon Instruments,
Inc. and is being used in Dr. Alison Murray’s lab: The latest
microarray scanner from Axon Instruments, Inc., the GenePix 4000B,
can run full two-color scans in five minutes at high resolution
with precise laser controls. We were lucky to receive a loaner
GenePix 4000B from Axon Inc. to bring on the Extreme2003 cruise.
DNA is usually in two strands — each has what we call complementary
sequences, meaning they match each other. Matching DNA will stick
together. We use this feature of DNA in a microarray, a glass
slide with thousands of different tiny spots of DNA printed on
it. To analyze a sample on a microarray, we use its RNA or DNA
and label it with a fluorescent dye so it is visible to the lasers
on the scanner. Then we incubate the labeled DNA or RNA with the
microarray, and labeled bits will stick to their complement on
the microarray. The Axon scanner uses lasers to detect the spots
of fluorescent DNA or RNA. The results tell us which sequences
of RNA or DNA were present in our sample and tell us about gene
expression. This is the first microarray scanner to go to sea.
|
|
|
|
Another loaner device is the NanoDrop ND-1000 Spectrophotometer
— a novel design of spectrophotometer that requires only 1.5 µL
sample volumes. This drastically decreases loss of sample during
measurement. In molecular biology, we generally use a spectrophotometer
to determine sample concentrations — in our case, nucleic
acids (RNA and DNA). A solution will absorb light based on its
concentration — the more stuff present in the sample, the more
light is absorbed. A spectrophotometer has a light on one side
and a detector on the other, and the sample goes in the middle.
The detector measures how much light passes through the sample
— if some is absorbed, then less light passes through it. By knowing
what is in the sample and what its absorbance is, we can calculate
the concentration of the sample — how much stuff is in it.
|
|
|
| The output from the NanoDrop is a spectrum showing the wavelengths at which light is absorbed, as shown by the peaks. Different chemicals absorb different colors of light. |
|
|
| Under
George’s
watchful eye, Tim
and Greg
begin preparation for the redeployment of the AIS InsECT, which
will go down tomorrow in Alvin’s basket. |
|
|
| Monika
emerges from the sub today all smiles, signaling a successful
dive. |
|
|
|
After Alvin is secured in the hangar, it is dehumidified
— old air is sucked out and fresh air is pumped into the hull.
|
|
|
| Tim
waits to see the saltwater crystallize on the thermometer due
to evaporation. |
|
|
| Pieces
of basalt collected today. The shiny material is the inner
core where temperatures are highest. |
|
|
|
Kay
gets to take the second dive of her lifetime. This time she knew
what to expect, and she was able to run several electrochemical
scans on the research site. |
|
|
|
View of one of Alvin’s portholes from inside the sub.
Notice the condensation that forms due to the temperature change
with depth. |
|
|
| The Large Volume Water Sampler (LVWS) at work on the seafloor. |
|
|
| Alvin’s
bright lights illuminate the deep sea. |
|
|
|
This deep-sea crab seems to be going “claw-to-claw” with Alvin’s
manipulator. |
|
