Item 12(a)(2).
CERTIFICATIONS |
| I, Edward C. Bernard, certify that: | ||
| 1. | I have reviewed this report on Form N-CSR of T. Rowe Price Health Sciences Fund; | |
| 2. | Based on my knowledge, this report does not contain any untrue statement of a material fact or omit | |
| to state a material fact necessary to make the statements made, in light of the circumstances under | ||
| which such statements were made, not misleading with respect to the period covered by this report; | ||
| 3. | Based on my knowledge, the financial statements, and other financial information included in this | |
| report, fairly present in all material respects the financial condition, results of operations, changes in | ||
| net assets, and cash flows (if the financial statements are required to include a statement of cash | ||
| flows) of the registrant as of, and for, the periods presented in this report; | ||
| 4. | The registrant's other certifying officer(s) and I are responsible for establishing and maintaining | |
| disclosure controls and procedures (as defined in rule 30a-3(c) under the Investment Company Act | ||
| of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the | ||
| Investment Company Act of 1940) for the registrant and have: | ||
| (a) Designed such disclosure controls and procedures, or caused such disclosure controls and | ||
| procedures to be designed under our supervision, to ensure that material information relating to | ||
| the registrant, including its consolidated subsidiaries, is made known to us by others within those | ||
| entities, particularly during the period in which this report is being prepared; | ||
| (b) Designed such internal control over financial reporting, or caused such internal control over | ||
| financial reporting to be designed under our supervision, to provide reasonable assurance | ||
| regarding the reliability of financial reporting and the preparation of financial statements for | ||
| external purposes in accordance with generally accepted accounting principles; | ||
| (c) | Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in | |
| this report our conclusions about the effectiveness of the disclosure controls and procedures, as of | ||
| a date within 90 days prior to the filing date of this report based on such evaluation; and | ||
| (d) | Disclosed in this report any change in the registrant’s internal control over financial reporting that | |
| occurred during the second fiscal quarter of the period covered by this report that has materially | ||
| affected, or is reasonably likely to materially affect, the registrant’s internal control over financial | ||
| reporting; and | ||
| 5. | The registrant's other certifying officer(s) and I have disclosed to the registrant's auditors and the | |
| audit committee of the registrant's board of directors (or persons performing the equivalent | ||
| functions): | ||
| (a) | All significant deficiencies and material weaknesses in the design or operation of internal control | |
| over financial reporting which are reasonably likely to adversely affect the registrant's ability to | ||
| record, process, summarize, and report financial information; and | ||
| (b) | Any fraud, whether or not material, that involves management or other employees who have a | |
| significant role in the registrant's internal control over financial reporting. | ||
| Date: | August 17, 2007 | /s/ Edward C. Bernard |
| Edward C. Bernard | ||
| Principal Executive Officer |
CERTIFICATIONS |
| I, Joseph A. Carrier, certify that: | ||
| 1. | I have reviewed this report on Form N-CSR of T. Rowe Price Health Sciences Fund; | |
| 2. | Based on my knowledge, this report does not contain any untrue statement of a material fact or omit | |
| to state a material fact necessary to make the statements made, in light of the circumstances under | ||
| which such statements were made, not misleading with respect to the period covered by this report; | ||
| 3. | Based on my knowledge, the financial statements, and other financial information included in this | |
| report, fairly present in all material respects the financial condition, results of operations, changes in | ||
| net assets, and cash flows (if the financial statements are required to include a statement of cash | ||
| flows) of the registrant as of, and for, the periods presented in this report; | ||
| 4. | The registrant's other certifying officer(s) and I are responsible for establishing and maintaining | |
| disclosure controls and procedures (as defined in rule 30a-3(c) under the Investment Company Act | ||
| of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the | ||
| Investment Company Act of 1940) for the registrant and have: | ||
| (a) Designed such disclosure controls and procedures, or caused such disclosure controls and | ||
| procedures to be designed under our supervision, to ensure that material information relating to | ||
| the registrant, including its consolidated subsidiaries, is made known to us by others within those | ||
| entities, particularly during the period in which this report is being prepared; | ||
| (b) Designed such internal control over financial reporting, or caused such internal control over | ||
| financial reporting to be designed under our supervision, to provide reasonable assurance | ||
| regarding the reliability of financial reporting and the preparation of financial statements for | ||
| external purposes in accordance with generally accepted accounting principles; | ||
| (c) | Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in | |
| this report our conclusions about the effectiveness of the disclosure controls and procedures, as of | ||
| a date within 90 days prior to the filing date of this report based on such evaluation; and | ||
| (d) | Disclosed in this report any change in the registrant’s internal control over financial reporting that | |
| occurred during the second fiscal quarter of the period covered by this report that has materially | ||
| affected, or is reasonably likely to materially affect, the registrant’s internal control over financial | ||
| reporting; and | ||
| 5. | The registrant's other certifying officer(s) and I have disclosed to the registrant's auditors and the | |
| audit committee of the registrant's board of directors (or persons performing the equivalent | ||
| functions): | ||
| (a) | All significant deficiencies and material weaknesses in the design or operation of internal control | |
| over financial reporting which are reasonably likely to adversely affect the registrant's ability to | ||
| record, process, summarize, and report financial information; and | ||
| (b) | Any fraud, whether or not material, that involves management or other employees who have a | |
| significant role in the registrant's internal control over financial reporting. | ||
| Date: | August 17, 2007 | /s/ Joseph A. Carrier |
| Joseph A. Carrier | ||
| Principal Financial Officer |