4. Barrow, Alaska: Processing the Cores
Since his return Brian has processed his ice cores by cutting each core into 10cm lengths to produce a depth profile for each sample. These 10cm cores are then cut into two halves so that one half can be archived and used, if needed. The half selected for processing is allowed to melt and a stain is added to visualize the nuclear DNA of any organisms present in the water. These organisms are then counted using a fluorescent microscope. A second sample will be used to extract DNA from the microorganisms, which is then amplified using the Polymerase Chain Reaction (PCR). This DNA is then separated using Denature Gradient Gel Electrophoresis (DGGE) and is sequenced and compared with an on-line database to identify the species that are present.
