Significant Accounting Policies (Tables)
 12 Months Ended
Dec. 31, 2015
Accounting Policies [Abstract]  
Schedule of Goodwill
Goodwill (in thousands)
Balance, December 31, 2013
 
$
—

Purchased through acquisitions of Gentris and BioServe
 
3,187

Balance, December 31, 2014
 
3,187

Purchased through acquisition of Response Genetics
 
8,842

Balance, December 31, 2015
 
$
12,029
Computation of Basic Net Income (Loss) and Diluted Net Loss per Share Data
Basic net loss and diluted net loss per share data were computed as follows (in thousands, except per share amounts): 
 
 
2015
 
2014
 
2013
Numerator:
 
 
 
 
 
 
Net (loss) for basic earnings per share
 
$
(20,184
)
 
$
(16,643
)
 
$
(12,373
)
Less change in fair value of warrant liability
 
35

 
417

 
4,633

Net (loss) for diluted earnings per share
 
$
(20,219
)
 
$
(17,060
)
 
$
(17,006
)
Denominator:
 
 
 
 
 
 
Weighted-average basic common shares outstanding
 
10,298

 
9,449

 
4,665

Assumed conversion of dilutive securities:
 
 
 
 
 
 
Common stock purchase warrants
 
1

 
13

 
11

Potentially dilutive common shares
 
1

 
13

 
11

Denominator for diluted earnings per share—adjusted weighted-average shares
 
10,299

 
9,462

 
4,676

Basic net loss per share
 
$
(1.96
)
 
$
(1.76
)
 
$
(2.65
)
Diluted net loss per share
 
$
(1.96
)
 
$
(1.80
)
 
$
(3.64
)
Summary of Potentially Dilutive Adjustments to Weighted Average Number of Common Shares Excluded from Calculation
The following table summarizes potentially dilutive adjustments to the weighted average number of common shares which were excluded from the calculation (in thousands):
 
 
2015
 
2014
 
2013
Common stock purchase warrants
 
4,372

 
1,061

 
1,702

Stock options
 
1,961

 
1,839

 
874

Restricted shares of common stock
 
121

 
133

 
7

 
 
6,454

 
3,033

 
2,583