The top after-market Nasdaq gainers Tuesday were RPX Corporation, Comcast Corporation, Unilife Corp, and Quality Distribution Inc, while the top after-market Nasdaq losers were Natural Alternatives International, NETGEAR Inc, Buffalo Wild Wings and Blue Nile.

Gainers

RPX Corporation (NASDAQ:RPXC) shares gained 12.25 percent to $12.00 in post-market trading. RPX Corp reported adjusted earnings per share of $0.24 beating the analysts’ estimate of $0.19. It reported revenues of $51.56 million topping the average revenue estimate of $49.02 million.

Comcast Corporation Inc (NASDAQ:CMCSA) shares climbed 7.13 percent to $41.75 in post-market trading Tuesday. The company announced Tuesday, it will acquire GE's entire 49 percent common equity stake in the NBCUniversal joint venture for approximately $16.7 billion. Also, NBCUniversal will purchase from GE the properties used by NBCUniversal at 30 Rockefeller Plaza and CNBC's headquarters in Englewood Cliffs, NJ, for approximately $1.4 billion.

Unilife Corp (NASDAQ:UNIS) shares advanced 4.81 percent to $2.18 in post-market trading. The stock has a 52-week low of $2.01, a 52-week high of $5.17 and $173.18 million in market capitalization.

Quality Distribution Inc (NASDAQ:QLTY) shares gained 4.68 percent to $8.50 in post-market trading. The company announced for the fourth quarter of 2012, it expects its total revenue to be approximately $215 million, operating income to be in the range of $9.9-$10.6 million, adjusted EBITDA to be within the range of $20 million to $20.7 million. According to analysts’ estimates, the Company was expected to report revenue of $200.9 million, EBIT of $11.9 million and EBITDA of $18.8 million for fourth quarter of 2012.

Losers

Natural Alternatives International (NASDAQ:NAII) shares declined 7.44 percent to $4.85 in post-market trading. The company announced its second quarter results Tuesday and reported a decrease in net sales by $2.5 million or 15.3 percent from $16.2 million recorded in the same period last year. A net income for the first six months of fiscal 2013 totaled $799,000 or $0.12 per diluted share, compared to net income of $2.3 million or $0.33 per diluted share in the comparable prior year period.

NETGEAR Inc (NASDAQ:NTGR) shares dropped 7.40 percent to $33.80 in post-market trading. The Company reported fourth quarter non-GAAP earnings per share of $0.55 after the bell Tuesday, down from $0.69 in the prior year period. The consensus estimate was for EPS of $0.54. Net revenue was $310.4 million, compared to $309.2 million last year against the consensus estimate of revenues of $307.7 million.

Buffalo Wild Wings (NASDAQ:BWLD) shares slumped 4.70 percent to $77.26 in post-market trading. The company stock has a 52-week low of $68.71, a 52-week high of $94.81 and $1.51 billion in market capitalization.

Blue Nile Inc (NASDAQ:NILE) shares fell 4.10 percent to $29.70 in post-market trading. The company reported fourth quarter earnings per share of $0.39, $0.08 worse than the analyst estimate of $0.47. Revenue for the quarter came in at $136.1 million versus the consensus estimate of $145.62 million.

Comcast