Sometimes Jim Cramer tells a caller that he needs to do homework before he can make a decision on a stock. And he's not kidding.

Following is Cramer's research or homework on stocks recently called to his attention by investors who watch the TV show.

Inovio

On March 17th, Michael in Illinois asked about Inovio, then on Thursday's Lightning Round, Chris in New York asked about the same name.

"I don't know enough about this stock to opine," said Cramer at the time. "I need to do some homework."

Fortunately Cramer is a quick study. In a day's time, he's learned that Inovio is a small biotech company that has run from about $0.50/share a year ago to well over $3/share today.

Largely the gains are pegged to the promise of vaccines made by the company that are used in the treatment of cancers and infectious diseases. "The company's SynCon technology enables vaccines to protect patients from changing strains of pathogens, including influenza and HIV. And the clinical programs include cervical dysplasia, avian influenza, prostate cancer, leukemia, Hep C and HIV. "

Cramer always says "Mad Money" viewers are among the smartest investors that he knows. And this is no exception. He thinks viewers have found a potential buy.

"I believe that the pipeline breadth makes an interesting spec," he said. But, as with every spec play, Cramer also added a word of caution. "If you go into this stock, you must realize it's a bet on a very early stage pipeline and the bet could go wrong."

Turquoise Hill

On March 11th, Rowland in Massachusetts asked about Turquoise Hill, formerly Ivanhoe Mines.

Cramer's research shows that the company is an international exploration and development mining company with significant assets in Mongolia.

Although Cramer can see Turquoise Hill becoming a top copper producer, he wouldn't put money to work here, even with shares down 45% year to date. "There's a dispute with the government of Mongolia over the mines. Who knows how it will play out? Typically I stay away from stocks facing such uncertain catalysts."

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Alimera

On Mach 18th, Mav in California asked about Alimera, a small biotech that specializes in treatments for the eyes..

"It has one advanced product called ILUVIEN that is in development for DME, a disease of the retina that affects individuals with diabetes and can lead to vision loss and blindness," Cramer said.

Although the treatment shows promise, Cramer feels the stock is a somewhat binary bet on the drug's approval in the US.

"While updates on this could provide for upside, I think positions in Regeneron and Allergan remain a safer ways for investors to play the eye space," he said.

Call Cramer: 1-800-743-CNBC

Questions for Cramer? madmoney@cnbc.com

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