Casdin files Form 4: Director sells 500k BLFS shares, keeps 7.21M stake

Rhea-AI Filing Summary

Casdin Partners Master Fund, L.P. reported an insider sale of BioLife Solutions, Inc. (BLFS) common stock on 08/11/2025. The filing shows a reported sale of 500,000 shares at a price of $22.60 per share. The transaction is recorded with transaction code S indicating a disposition.

The filing identifies related reporting entities—Casdin Capital, LLC; Casdin Partners GP, LLC; and Eli Casdin—and states the securities are owned directly by the Master Fund and may be indirectly beneficially owned by those entities. After the reported transaction the reporting persons are shown as beneficially owning 7,207,165 shares indirectly.

Positive

• Transparent disclosure of an insider transaction by Casdin and affiliated entities
• Continued substantial indirect ownership of 7,207,165 shares after the sale
• Reporting identifies relationships between the Master Fund, adviser, GP, and Eli Casdin

Negative

• Insider disposition of 500,000 BLFS shares reported (Transaction Code S) at $22.60 per share
• Reporting person is a director and 10% owner, which may be viewed negatively by some investors

Insights

Financial Analyst

TL;DR: A 10% owner and affiliated entities disclosed a sale of 500,000 BLFS shares at $22.60, while retaining substantial indirect ownership.

The Form 4 reports a disposition (code S) of 500,000 shares of BioLife Solutions on 08/11/2025 at $22.60 per share by Casdin Partners Master Fund, L.P. The filing also shows continued indirect beneficial ownership of 7,207,165 shares through affiliated entities. From a market perspective, the filing increases transparency about insider activity; no derivative transactions or additional material changes to ownership structure are disclosed. The information is factual and allows investors to see a change in insider holdings without further context on motive or timing.

Corporate Governance Expert

TL;DR: Disclosure appears complete: affiliated entities and beneficial ownership are clearly identified after an insider sale.

The Form 4 names the reporting persons and their relationships to the issuer, and includes an explanation that the securities are directly owned by the Master Fund and may be indirectly beneficially owned by Casdin Capital, Casdin Partners GP, and Eli Casdin. The document records the disposition and the resulting indirect beneficial ownership of 7,207,165 shares. The filing demonstrates compliance with Section 16 disclosure requirements; it does not disclose any governance changes or additional agreements affecting control.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
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hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Casdin Partners Master Fund, L.P.

(Last) (First) (Middle)

1350 AVENUE OF THE AMERICAS

SUITE 2600

(Street)

NEW YORK NY 10019

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
BIOLIFE SOLUTIONS INC [ BLFS ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
08/11/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

	Form filed by One Reporting Person
X	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock, par value $0.001 per share	08/11/2025		S		500,000	D	$22.6	7,207,165	I	See Footnote(1)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person^*

Casdin Partners Master Fund, L.P.

(Last) (First) (Middle)

1350 AVENUE OF THE AMERICAS

SUITE 2600

(Street)

NEW YORK NY 10019

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Casdin Capital, LLC

(Last) (First) (Middle)

1350 AVENUE OF THE AMERICAS

SUITE 2600

(Street)

NEW YORK NY 10019

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Casdin Partners GP, LLC

(Last) (First) (Middle)

1350 AVENUE OF THE AMERICAS

SUITE 2600

(Street)

NEW YORK NY 10019

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Casdin Eli

(Last) (First) (Middle)

1350 AVENUE OF THE AMERICAS

SUITE 2600

(Street)

NEW YORK NY 10019

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

Explanation of Responses:

1. The securities are owned directly by Casdin Partners Master Fund, L.P. (the "Master Fund") and may be deemed to be indirectly beneficially owned by (i) Casdin Capital, LLC ("Casdin Capital"), the investment adviser to the Master Fund, (ii) Casdin Partners GP, LLC ("Casdin GP"), the general partner of the Master Fund, and (iii) Eli Casdin, the managing member of Casdin Capital and Casdin GP.

	Casdin Partners Master Fund, LP, By: Casdin Partners GP, LLC,, its General Partner, By: /s/ Eli Casdin, Managing Member	08/13/2025
	Casdin Capital LLC, By: /s/ Eli Casdin, Managing Member	08/13/2025
	Casdin Partners GP LLC, By: /s/ Eli Casdin, Managing Member	08/13/2025
	/s/ Eli Casdin, Eli Casdin	08/13/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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FAQ

What transaction was reported for BLFS by Casdin Partners?

The Form 4 reports a sale of 500,000 shares of BioLife Solutions common stock on 08/11/2025 with transaction code S.

At what price were the BLFS shares sold in the Form 4?

The reported sale price was $22.60 per share.

How many BLFS shares do the reporting persons beneficially own after the transaction?

Following the reported transaction the filing shows 7,207,165 shares beneficially owned indirectly.

Which entities and individuals are listed as reporting persons on the Form 4?

The reporting persons are Casdin Partners Master Fund, L.P., Casdin Capital, LLC, Casdin Partners GP, LLC, and Eli Casdin.

Does the filing indicate any derivative transactions or options?

No. Table II for derivative securities contains no entries; only a non-derivative sale is reported.