cell-phone-recharge kiosks, the fruit markets, the meat markets, the open-air hardware stores, the tire-repair shops and cement brokers, the piles of sand and gravel and garbage, the awesome decrepitude of a postcolonial metropolis shaped by eight decades of Belgian opportunism, three decades of dictatorial misrule and egregious theft, and then a decade of war, but filled with 10 million striving people, some of whom are dangerous thugs (as in all cities) and most of whom are amiable, hopeful, and friendly. The university campus, on its hill, loosely called “the mountain,” presents a relatively verdant and halcyon contrast to the city below. Students go there, climbing by foot from a crowded bus stop, to learn and to escape.
Professor Jean-Marie M. Kabongo is head of pathology in the university’s Department of Anatomic Pathology. He’s a small, natty man with a huge graying handlebar mustache and full muttonchops, making a forceful visual impression that’s vitiated by his gentle manner. When I met him in his office, on the second floor of a building that overlooks a grassy concourse shaded with acacias, he pleaded imperfect knowledge of DRC60 and the patient from whom that specimen came. An old case, after all, going back long before his time. Yes, a woman, he believed. His memory was vague but he could check the records. He began taking notes as I questioned him and suggested I come back in a couple days, when he might be better prepared with answers. But then I asked about the room where DRC60 had been stored, and he brightened. Oh, of course, he said, I can show you that.
He fetched a key. He unlocked a blue door. Swinging it open, he welcomed me into a large sunlit laboratory with walls of white tile and two long, low tables down the middle. On one of the tables rested an old-fashioned folio ledger, with curling pages, like something from Chancery in the time of Dickens. On the far windowsill stood a row of beakers containing liquids in increments of color, beaker by beaker, from piss-yellow to vodka-clear. The yellowest, Professor Kabongo told me, was methanol. The clearest was xylol. We use these in preparing a tissue sample, he said. The point of such organic solvents is to extract the water; desiccation is prerequisite to fixing tissues for the long term. The methanol was darkened from processing many samples.
He showed me a small orange plastic basket, with a hinged lid, about the size and shape of a matchbook. This is a “cassette,” Professor Kabongo explained. You take a lump of tissue from a lymph node or some other organ and enclose it in such a cassette; you soak the whole thing in the beaker of methanol; from the methanol, it goes through the intermediate baths in sequence; finally you dunk it in the xylol. Methanol draws out the water; xylol draws out the methanol, preparing your specimen for preservation in paraffin. And this device, Professor Kabongo said, indicating a large machine on one of the tables, delivers the paraffin. You take a leached tissue sample from its cassette, he explained, and, from that spigot, you dribble out a stream of warm, liquid paraffin. It cools on the sample like a pat of butter. Now you remove the cassette lid and label the base with an individual code—for instance, A90 or B71. That’s your archival specimen, he said. “A” means that it came from an autopsy. “B” indicates a biopsy. So the paraffin-caked bit of lymph node that yielded DRC60 would have been labeled B-something. Each coded specimen gets recorded in the big ledger. Then the specimens go into storage.
Storage. Storage where? I asked.
At the far end of the lab was another doorway, this one hung with a blue curtain. Professor Kabongo pushed the curtain aside and I followed him into a specimen pantry, narrow and tight, lined with shelves and cabinets along one side. The shelves and cabinets contained thousands of dusty paraffin blocks and old microscope slides. The paraffin blocks were in stacks and cartons, some of the cartons dated, some not. It appeared to be organized chaos. A wooden stool awaited use by any curious, tireless soul wishing to rummage through the samples. Although I didn’t plan to rummage, my tour had suddenly come to its crescendo. Here? Yes, just here, said the professor. This is where DRC60 sat for decades. He could have added, with local pride: before becoming a Rosetta stone in the study of AIDS.