Exhibit 12.1 QUEST DIAGNOSTICS INCORPORATED COMPUTATION OF RATIO OF EARNINGS TO COMBINED FIXED CHARGES AND PREFERRED DIVIDENDS (DOLLARS IN THOUSANDS, EXCEPT RATIOS) FOR THE SIX MONTHS YEAR ENDED DECEMBER 31, ENDED ----------------------------------------------------------------- JUNE 30, 2003 2002 2001 2000 1999 1998 --------- ----------------------------------------------------------------- Income before taxes, equity earnings and minority share of income ..................... $351,596 $ 539,177 $330,720 $204,002 $ 20,473 $ 61,070 Adjustments: Distributed income from less than 50% owned companies ........ 7,490 17,034 3,620 2,952 1,740 -- Fixed charges ....................... 50,434 89,567 105,154 145,721 89,336 59,242 -------- --------- --------- --------- ---------- ---------- Earnings before taxes and fixed charges, as adjusted ................ $409,520 $ 645,778 $439,494 $352,675 $ 111,549 $ 120,312 ======== ========= ========= ========= ========== ========== Fixed charges: Interest expense .................... $ 31,389 $ 57,707 $ 77,840 $120,471 $ 69,842 $ 43,977 Portion of rent expense which represents interest factor ...... 19,045 31,860 27,314 25,250 19,494 15,265 -------- --------- --------- --------- ---------- ---------- Total fixed charges ................... $ 50,434 $ 89,567 $105,154 $145,721 $ 89,336 $ 59,242 ======== ========= ========= ========= ========== ========== Preferred dividends: Preferred dividend requirements ..... $ -- $ -- $ 118 $ 118 $ 118 $ 118 Ratio of pre-tax income to income (loss) before extraordinary loss............... 1.7 1.7 1.8 1.9 (11.3) 2.0 -------- --------- --------- --------- ---------- ---------- Pre-tax preferred dividend requirement ..................... -- -- 212 225 (1,327) 235 Total fixed charges ................... 50,434 89,567 105,154 145,721 89,336 59,242 -------- --------- --------- --------- ---------- ---------- Fixed charges and pre-tax preferred dividend requirement .. $ 50,434 $ 89,567 $105,366 $145,946 $ 88,009 $ 59,477 ======== ========= ========= ========= ========== ========== Ratio of earnings to fixed charges .... 8.1x 7.2x 4.2x 2.4x 1.2x 2.0x Ratio of earnings to combined fixed charges and preferred dividends ..... 8.1x 7.2x 4.2x 2.4x 1.3x 2.0x )