New Ultraviolet Ray Microscope Probes Mysteries of Cell Cancer

A small group of Harvard scientists working in a stone building several blocks behind MIT have succeeded in unlocking the doors that have blocked man from seeing brilliant colors in regions that have in the past been visible only as murky, drab swirls.

These colors, caused by minute variations in the chemical characteristics of the cells that make up living tissue, have enabled cancer researchers to probe deeper than ever before into the mysterious factors that differentiate healthy tissue from cancerous tissue.

Ultraviolet Microscope

The device that makes the research possible is a color translating, ultraviolet microscope developed by the Polaroid Comporation, a Cambridge firm that astounded the optical world 12 years ago by producing the first practical means of polarizing light.

The new microscope, which cost a third of a million dollars to develop and build, is so revolutionary in principle that scientists associated with the project had to start practically from scratch anl develop whole new areas of theory. According to William A. Shurcliff '40, Polaroid physicist who co-ordinated teams of physicists, chemists, and biologists on the project. "We had to throw everything we knew about microscopes out of the window."

Math Took a Year

The most remarkable piece of research done in making the microscope was the was the objective lens designed by David S. Gray '40, Gray's problem was to design a high-powered lens that would be simultaneously transparent to both ultra-violet and normal light without re-focussing. Mathematical calculations alone took the young scientist, who is regarded as among the five or so top lens designers in the world, over a year.

The new lens was the fundamental stumbling block, and once it was completed, other men went to work on an apparatus that would house the tiny piece of glass and enable it to perform its amazing function. Robert C. Jones '38, designed an electronic brain that instantly calculates the exposure settings on the camera to which the lens is coupled. Murray N. Fairbank '28, chief engineer on the project, developed the maze of machinery that feeds the film through the equipment and develops it in a minute's time.

Extends Vision Whole Octave

Performance of the machine has shown its possibilities to be almost limitless. It extends the range of man's color vision down one whole octave into the shorter wave length to a region never seen before. This is done by making use of the ultra-violet light emitted by living tissues when photographed under the extremely short wavelengths of ultraviolet light.

Three different photographs of a specimen are taken on film sensitive to the ultraviolet end of the light spectrum. These three exposures are made at three different wavelengths which correspond to the fundamental red, yellow, and blue of ordinary light. In the few seconds after exposure the instrument develops the films, dries them, and projects them through color filters onto a viewing screen.

Cancer Shown in Red

The result is a picture of the specimen that is in full color, while to the ordinary microscope, human tissue is completely colorless. Amazing things have been seen with the new instrument. Cancerous cells, which have heretofore in many cases been impossible to distinguish from healthy tissue, have been seen on the screen as flaming red inflammations on the green background of normal tissue. These colors are produced by chemical reactions within the cells.

Biologists are tremendously excited by the microscope. The variations in color between healthy and diseased cells may lead to a better understanding of the whole life process Shurcliff says the device offers "new eyes to see a whole world."

Sharpness Increased

Besides revealing colors in regions where color has never been seen before the ultraviolet light, because of its shorter wave length, enlarges with twice the clarity of ordinary microscopes, enabling scientists to observe twice as much detail as has been seen before.

The microscope is too new to have made any significant contributions yet to medicine. Tests are being conducted continuously, and the results still amaze the experimenters. Operator of the machine is young, good-looking Miss Marian Swaffield, a Wellesley-trained expert in cell biology. She and others are working on projects sponsored jointly by the Office of Naval Research and the American Cancer Society.

To view a specimen in the instrument, Miss Swaffield places it on the microscope stage and presses a button. A minute later she sees a full-color view of the object as it would look if her eyes were tuned in for the short ultraviolet rays.

Idea Was Land's

The initial idea of the ultraviolet microscope is the product of Edwin H. Land '31, a Ph.D. physicist and President and Director of research of the Polaroid Corporation. While working on other research in 1948, he got the idea of the application of polarized screens to the ultraviolet source.

Other Polaroid scientists soon joined him in the initial attacks upon theory. The first problem met was exactly what kind of device they wanted. What wave-length could best aid the biologists? What did the biologists want to find? Then there was the problem of how to make it, the core of which was the apparently insurmountable difficulty of designing the lens. Gray's work came at an opportune time, for at the beginning there were many doubts.

Work Slow at First

Finally, there were operational problems. Would the ultraviolet rays and the heat kill the very substances they were trying to probe? Work proceeded slowly at first, but under Shurcliff's guidance, the experts in all the various fields fitted their individual labor together in the final coordination of the project. First use of the microscope came early this spring.

Fundamental to the whole program and to many modern optical miracles is the discovery by Land in 1938 of the first practical way to polarize light by synthetic means. Land at the time was a graduate student in the Department of Physics. According a legend, Land first became interested in optics as a student in the basic Physics course, then Physics A.

A means had been developed before to polarize light, but it involved the use of quartz crystals, which were arranged so that the crystal lattice was aligned along one axis. Light would be transmitted freely by one axis of the crystals, but it would be blocked entirely by the other axis. This worked--in theory. But in practice, a perfect alignment of the crystals was impossible, and their sizes made the apertures through which light passed comparatively small.

Secret is Stretched Plastic

Studying this method, Land realized that the process might work better on the molecular scale. He finally worked out a means in which a sheet of polyvinyl alcohol a thick plastic--was stretched. In the stretching, the molecules of the plastic would align themselves with their poles in the same direction. Land had a cheap, permanent device that was far more efficient, both in the transmission and the exclusion of light, than was its crystal predecessor.

The amazing property of the polarizing screen to cut glare soon won him a host of backers, and the Polaroid Corporation was founded with Land as President. The polarizers were to form the fundamental tool in the development of many new optical projects, many still completely "classified" because of their defense value. Land is the inventor of the Polaroid-Land camera, which enables the amateur photographer to take a picture and see it developed in less than one minute.

But the project that has the widest horizon is the ultraviolet microscope. Its prospects as an aid to medical scientists in their probe of the mysteries of life appear limitless.