4. GOODWILL AND OTHER PURCHASED INTANGIBLE ASSETS
Changes to goodwill by segment were as follows (in millions): | | | | | | | | | | | | | | | | | | | Life Science | | Clinical Diagnostics | | Total | | Balances as of December 31, 2025 | | | | | | | Goodwill | $ | 493.2 | | | $ | 421.8 | | | $ | 915.0 | | | Accumulated impairment losses | (41.8) | | | (293.4) | | | (335.2) | | | Goodwill, net | 451.4 | | | 128.4 | | | 579.8 | | | | | | | | | | | | | | | Acquisition adjustments | (1.1) | | | — | | | (1.1) | | | | | | | | | Foreign currency adjustments | (4.4) | | | — | | | (4.4) | | Period change, net | (5.5) | | | — | | | (5.5) | | | | | | | | | Balances as of June 30, 2026 | | | | | | | Goodwill | 487.7 | | | 421.8 | | | 909.5 | | | Accumulated impairment losses | (41.8) | | | (293.4) | | | (335.2) | | | Goodwill, net | $ | 445.9 | | | $ | 128.4 | | | $ | 574.3 | |
Information regarding our identifiable purchased intangible assets with finite and indefinite lives is as follows (in millions): | | | | | | | | | | | | | | | | | | | | | | | | | June 30, 2026 | | Weighted-Average Amortization Period (in years) | | Purchase
Price | | Accumulated
Amortization | | Net Carrying Amount | | Customer relationships/lists | 3.9 | | $ | 114.1 | | | $ | (107.2) | | | $ | 6.9 | | | | | | | | | | | Developed product technology | 10.4 | | 311.8 | | | (167.5) | | | 144.3 | | | Licenses | 2.6 | | 59.5 | | | (51.5) | | | 8.0 | | | Tradenames | 3.1 | | 6.0 | | | (5.2) | | | 0.8 | | | Covenants not to compete | — | | 6.5 | | | (6.5) | | | — | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Total purchased intangible assets | | | $ | 497.9 | | | $ | (337.9) | | | $ | 160.0 | |
| | | | | | | | | | | | | | | | | | | | | | | | | December 31, 2025 | | Weighted-Average Amortization Period (in years) | | Purchase
Price | | Accumulated
Amortization | | Net Carrying Amount | | Customer relationships/lists | 4.4 | | $ | 115.6 | | | $ | (107.7) | | | $ | 7.9 | | | | | | | | | | | Developed product technology | 10.7 | | 315.8 | | | (160.0) | | | 155.8 | | | Licenses | 3.1 | | 59.8 | | | (50.3) | | | 9.5 | | | Tradenames | 3.6 | | 6.0 | | | (5.1) | | | 0.9 | | | Covenants not to compete | 0.5 | | 6.5 | | | (6.3) | | | 0.2 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Total purchased intangible assets | | | $ | 503.7 | | | $ | (329.4) | | | $ | 174.3 | |
Amortization expense related to purchased intangible assets was as follows (in millions):
| | | | | | | | | | | | | | | | | | | | | | | | | Three Months Ended | | Six Months Ended | | June 30, | | June 30, | | 2026 | | 2025 | | 2026 | | 2025 | | Amortization expense | $ | 6.0 | | | $ | 5.2 | | | $ | 11.9 | | | $ | 10.2 | |
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