On school days, Rachel Garner leads a busy life. Majoring in molecular, cell and developmental biology and minoring in the classics and political science, the medical school-bound senior has also done research in biological chemistry.

But it's for the weekends that Garner saves much of her energy and passion. That's when she volunteers in a UCLA science lab teaching molecular biology to inner-city high school students.

Garner is among some 40 UCLA undergraduates who volunteer on many Saturdays to work in CityLab with Los Angeles high school students on science experiments. The program offers the kind of experience that Garner said she would have loved when she was in high school.

"My high school didn't offer advanced placement biology," Garner said. "We did animal dissections, but no molecular biology research. Entering college, I felt there was so much I didn't know. A lot of high school students are potentially interested in many subjects, but unless someone sparks their interest, they might not pursue it."

CityLab provides that spark through these undergraduates. Hundreds of students from such high schools as Compton, Inglewood, Venice, James Monroe, Morningside, Lawndale and Fairfax have learned from them.

"The UCLA students put their heart and soul into CityLab and are excellent teachers, and so enthusiastic," said L. Jeanne Perry, the faculty member in molecular, cell and developmental biology in whose lab the CityLab sessions are held. "The high school students start visualizing themselves as college students; when they see the UCLA students in the lab, some can see themselves in a few years."

In fact, said Audrey Cramer, director of UCLA's Life and Physical Sciences Undergraduate Research Center and program adviser, evaluations indicate that many of the high school participants decide to apply to college and declare a science major after being in the program.

That's exactly what the UCLA students hope will happen.

"My parents always emphasized education, but a lot of other kids don't have that advantage," Garner said. "I try to offer some of that encouragement to others who might need it. By teaching what I've learned in biology and chemistry to high school students, I'm able to pass on that knowledge. That shows me that I learned it for a reason."

Learning science this way - "to actually do what UCLA students and researchers do," one participant explained enthusiastically - is an experience they relish. To study sickle-cell anemia, for example, students not only learn the cause of the disease and a method to detect it, comparing red blood cells from healthy people with those of sickle-cell patients, but they use principles of genetics to determine the inheritance pattern of the disease and discuss treatment options.

Said Howard Fan, a UCLA senior and psychobiology major who is this year's director of CityLab: "We offer our time, our energy and enthusiasm and our passion for science."

For more information, e-mail CityLab at: citylab@ucla.edu.