United States

Top 70 largest US Companies in the Diagnostics & Research industry by Market Cap

This is the list of the largest public listed companies in the Diagnostics & Research industry from the United States by market capitalization with links to their reference stock.

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Top Diagnostics & Research Companies from the United States as of Jan. 01, 2026

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Rank Company Market Cap (USD) Country Sector Industry
1 Thermo Fisher Scientific Inc. $222.61 B United States US Healthcare US Diagnostics & Research
2 Danaher Corporation $164.98 B United States US Healthcare US Diagnostics & Research
3 IDEXX Laboratories, Inc. $53.62 B United States US Healthcare US Diagnostics & Research
4 Agilent Technologies, Inc. $39.11 B United States US Healthcare US Diagnostics & Research
5 IQVIA Holdings Inc. $38.38 B United States US Healthcare US Diagnostics & Research
6 Natera, Inc. $31.91 B United States US Healthcare US Diagnostics & Research
7 Mettler-Toledo International Inc. $29.07 B United States US Healthcare US Diagnostics & Research
8 DexCom, Inc. $26.09 B United States US Healthcare US Diagnostics & Research
9 Waters Corporation $22.74 B United States US Healthcare US Diagnostics & Research
10 Laboratory Corporation of America Holdings $20.91 B United States US Healthcare US Diagnostics & Research
11 Illumina, Inc. $20.65 B United States US Healthcare US Diagnostics & Research
12 Quest Diagnostics Incorporated $19.43 B United States US Healthcare US Diagnostics & Research
13 Exact Sciences Corporation $19.31 B United States US Healthcare US Diagnostics & Research
14 Medpace Holdings, Inc. $16.08 B United States US Healthcare US Diagnostics & Research
15 Guardant Health, Inc. $13.21 B United States US Healthcare US Diagnostics & Research
16 Revvity, Inc. $11.39 B United States US Healthcare US Diagnostics & Research
17 Charles River Laboratories International, Inc. $9.96 B United States US Healthcare US Diagnostics & Research
18 RadNet, Inc. $5.48 B United States US Healthcare US Diagnostics & Research
19 Sotera Health Company $5.03 B United States US Healthcare US Diagnostics & Research
20 Celcuity Inc. $4.65 B United States US Healthcare US Diagnostics & Research
21 Lantheus Holdings, Inc. $4.57 B United States US Healthcare US Diagnostics & Research
22 Syneos Health, Inc. $4.38 B

(July 1, 2023)

 United States US Healthcare US Diagnostics & Research
23 Ortho Clinical Diagnostics Holdings plc $4.19 B

(May 1, 2022)

 United States US Healthcare US Diagnostics & Research
24 Soleno Therapeutics, Inc. $2.53 B United States US Healthcare US Diagnostics & Research
25 Twist Bioscience Corporation $1.98 B United States US Healthcare US Diagnostics & Research
26 Quidel Corporation $1.96 B United States US Healthcare US Diagnostics & Research
27 NeoGenomics, Inc. $1.52 B United States US Healthcare US Diagnostics & Research
28 Neogen Corporation $1.52 B United States US Healthcare US Diagnostics & Research
29 Meridian Bioscience, Inc. $1.47 B

(Jan. 1, 2023)

 United States US Healthcare US Diagnostics & Research
30 Castle Biosciences, Inc. $1.12 B United States US Healthcare US Diagnostics & Research

Top Diagnostics & Research Companies from the United States as of Jan. 01, 2026

1. Thermo Fisher Scientific

Company Profile: Thermo Fisher Scientific Inc.
Market Cap (USD): $222.61 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

2. Danaher

Company Profile: Danaher Corporation
Market Cap (USD): $164.98 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

3. IDEXX Laboratories, Inc.

Company Profile: IDEXX Laboratories, Inc.
Market Cap (USD): $53.62 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

4. Agilent Technologies, Inc.

Company Profile: Agilent Technologies, Inc.
Market Cap (USD): $39.11 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

5. IQVIA Holdings Inc.

Company Profile: IQVIA Holdings Inc.
Market Cap (USD): $38.38 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

6. Natera, Inc.

Company Profile: Natera, Inc.
Market Cap (USD): $31.91 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

7. Mettler-Toledo International Inc.

Company Profile: Mettler-Toledo International Inc.
Market Cap (USD): $29.07 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

8. DexCom, Inc.

Company Profile: DexCom, Inc.
Market Cap (USD): $26.09 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

9. Waters Corporation

Company Profile: Waters Corporation
Market Cap (USD): $22.74 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

10. Laboratory Corporation of America Holdings

Company Profile: Laboratory Corporation of America Holdings
Market Cap (USD): $20.91 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

11. Illumina, Inc.

Company Profile: Illumina, Inc.
Market Cap (USD): $20.65 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

12. Quest Diagnostics Incorporated

Company Profile: Quest Diagnostics Incorporated
Market Cap (USD): $19.43 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

13. Exact Sciences Corporation

Company Profile: Exact Sciences Corporation
Market Cap (USD): $19.31 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

14. Medpace Holdings, Inc.

Company Profile: Medpace Holdings, Inc.
Market Cap (USD): $16.08 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

15. Guardant Health, Inc.

Company Profile: Guardant Health, Inc.
Market Cap (USD): $13.21 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

16. Revvity, Inc.

Company Profile: Revvity, Inc.
Market Cap (USD): $11.39 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

17. Charles River Laboratories International, Inc.

Company Profile: Charles River Laboratories International, Inc.
Market Cap (USD): $9.96 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

18. RadNet, Inc.

Company Profile: RadNet, Inc.
Market Cap (USD): $5.48 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

19. Sotera Health Company

Company Profile: Sotera Health Company
Market Cap (USD): $5.03 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

20. Celcuity Inc.

Company Profile: Celcuity Inc.
Market Cap (USD): $4.65 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

21. Lantheus Holdings, Inc.

Company Profile: Lantheus Holdings, Inc.
Market Cap (USD): $4.57 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

22. Syneos Health, Inc.

Company Profile: Syneos Health, Inc.
Market Cap (USD): $4.38 B (July 1, 2023)
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

23. Ortho Clinical Diagnostics Holdings plc

Company Profile: Ortho Clinical Diagnostics Holdings plc
Market Cap (USD): $4.19 B (May 1, 2022)
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

24. Soleno Therapeutics, Inc.

Company Profile: Soleno Therapeutics, Inc.
Market Cap (USD): $2.53 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

25. Twist Bioscience Corporation

Company Profile: Twist Bioscience Corporation
Market Cap (USD): $1.98 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

26. Quidel Corporation

Company Profile: Quidel Corporation
Market Cap (USD): $1.96 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

27. NeoGenomics, Inc.

Company Profile: NeoGenomics, Inc.
Market Cap (USD): $1.52 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

28. Neogen Corporation

Company Profile: Neogen Corporation
Market Cap (USD): $1.52 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

29. Meridian Bioscience, Inc.

Company Profile: Meridian Bioscience, Inc.
Market Cap (USD): $1.47 B (Jan. 1, 2023)
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

30. Castle Biosciences, Inc.

Company Profile: Castle Biosciences, Inc.
Market Cap (USD): $1.12 B
Country: United States
Sector: US Healthcare
Industry: US Diagnostics & Research

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