Terminal

They used the stairs. As they walked, Sean continued to explain. “Cytokines are protein molecules produced by cells of the immune system. They’re involved in cell-to-cell communication, signaling cues like when to grow, when to start doing their thing, when to get ready for an invasion of virus, bacteria, or even tumor cells. The NIH has been busy growing the lymphocytes of cancer patients in vitro with a cytokine called interleukin-2, then injecting the cells back into the patient. In some cases they’ve had some good results.”

“But not as good as the Forbes with their medulloblastoma cases,” Janet said.

“Definitely not as good,” Sean said.

Sean loaded himself and Janet with reagents from the storeroom; then they started back to his lab.

“This is an exciting time in biological science,” Sean said. “The nineteenth century was the century for chemistry; the twentieth century was the century for physics. But the twenty-first century will belong to molecular biology; it’s when all three—chemistry, physics, and biology—are going to merge. The results will be astounding, like science fiction come true. In fact, we’re already seeing it happen.”

By the time they got back in the lab Janet found herself becoming genuinely interested despite the day’s emotional traumas and her fatigue. Sean’s enthusiasm was infectious.

“What’s the next step with these medicines?” she asked.

“I’m not sure,” Sean admitted. “I suppose we should see what kind of reaction we get between the unknown antibody in the large vial and Helen Cabot’s tumor.”

Sean asked Janet to get out some scissors and a scalpel from a drawer near where she was standing. Sean took the cooler over to the sink, and after putting on a pair of latex rubber gloves, he lifted out the brain and rinsed it off. From beneath the sink he pulled out a cutting board. He put the brain on the board.

“I hope I don’t have trouble finding the tumor,” he said. “I’ve never tried to do anything like this before. Judging by the MRI we did in Boston, her largest tumor is in the left temporal lobe. That was the one they biopsied up there. I suppose that’s the one I should go after.” Sean oriented the brain so that he could determine the front from the back. Then he made several slices into the temporal lobe.

“I have an almost irresistible urge to joke about what I’m doing here,” he said.

“Please don’t,” Janet said. It was hard for her to deal with the fact that this was the brain of a person with whom she’d so recently related.

“Now this looks promising,” Sean said. He spread the edges of his most recent incision. At the base was a comparatively dense and more yellow-appearing tissue bearing tiny but visible cavities. “I think those spots might be areas where the tumor outgrew its own blood supply.”

Sean asked Janet to give him a hand, so she pulled on a pair of the rubber gloves and held the cut edges of the brain apart while Sean took a sample of the tumor with the scissors.

“Now we have to separate the cells,” he said, putting the sample in tissue culture medium, then adding enzymes. He put the flask in the incubator to give the enzymes a chance to work.

“Next we have to characterize this immunoglobulin,” he said, holding up the larger of the two vials of unknowns. “And to do this we have a test called ELISA where we use commercially made antibodies to identify specific types of immunoglobulins.” He placed the large vial on the countertop and picked up a plastic plate that had ninety-six tiny circular wells. In each of the wells he put a different capture antibody and allowed it to bind. Then he blocked any remaining binding sites in the wells with bovine serum albumin. Next he put a small aliquot of the unknown in each of the wells.

“Now I have to figure out which antibody has reacted to the unknown,” he said, washing each of the wells to rid them of any of the unknown immunoglobulin that hadn’t reacted. “We do this by adding to each well the same antibody that was originally in the well, only this time tagged with a compound that’s enzymatically capable of yielding a colored reaction.” This last substance had the characteristic of turning a pale lavender.

The whole time Sean was doing this test, he kept up a running explanation for Janet. She’d heard of the test but had never seen it performed.

“Bingo!” Sean said when one of the many wells turned the appropriate color to match controls he’d set up in sixteen of the end wells. “The unknown is no longer an unknown. It’s a human immunoglobulin called IgGl.”

“How did Forbes make it?” Janet asked.

“That’s a good question,” Sean said. “I’d guess by monoclonal antibody technique. Although it is not out of the question to make it by recombinant DNA technology. The problem there is that it’s a big molecule.”