Casdin Partners Sells 500K BLFS Shares; Holds 6.7M Post-Sale

Rhea-AI Filing Summary

Casdin Partners Master Fund, L.P. reported an insider sale of 500,000 shares of BioLife Solutions, Inc. (BLFS) on 08/15/2025 at a reported price of $24.40 per share. After the transaction, the Master Fund beneficially owned 6,707,165 shares, held indirectly. The Form 4 lists related reporting entities and individuals: Casdin Capital, LLC; Casdin Partners GP, LLC; and Eli Casdin, each identified as a director or related to the Master Fund, and signatures are dated 08/21/2025. The filing includes a disclosure that each reporting person disclaims beneficial ownership except to the extent of pecuniary interest.

Insights

Financial Analyst

TL;DR: A material insider sale of 500,000 shares was disclosed; holdings remain substantial at 6.7M shares.

The Form 4 documents a sale transaction of 500,000 common shares at $24.40 on 08/15/2025, reducing the reporting parties' position to 6,707,165 shares beneficially owned following the sale. This is a clear, time-stamped disclosure of insider activity and provides precise volume and price data required for market monitoring. The size of the remaining position indicates continued material exposure by the reporting entities. The filing contains standard disclaimers about pecuniary interest and indicates multiple related entities filed jointly.

Corporate Governance Expert

TL;DR: Routine Section 16 reporting by affiliated entities and an individual; documentation and signatures are complete.

The submission names the Master Fund as the direct owner and identifies Casdin Capital, Casdin Partners GP, LLC, and Eli Casdin as related reporting persons with indirect beneficial ownership. Signatures from the entities and Eli Casdin are dated 08/21/2025, and the explanatory footnote clarifies the ownership chain. The Form 4 appears properly executed and includes the customary disclaimer; no additional governance actions or amendments are reported within this filing.

Insider Trade Summary

Net Seller: 500,000 shares ($12,200,000)

Net Sell 1 txn

Insider Casdin Partners Master Fund, L.P., Casdin Capital, LLC, Casdin Partners GP, LLC, Casdin Eli

Role 10% Owner | 10% Owner | 10% Owner | 10% Owner

Sold 500,000 shs ($12.20M)

Type	Security	Shares	Price	Value
Sale	Common Stock, par value $0.001 per share	500,000	$24.40	$12.20M

Holdings After Transaction: Common Stock, par value $0.001 per share — 6,707,165 shares (Indirect, See footnote.)

Footnotes (1)

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Form 4 Insider Transactions: What Each Field Means →

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
Estimated average burden
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)
08/15/2025

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	08/15/2025		S		500,000	D	$24.4	6,707,165	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.

Remarks:

Each Reporting Person disclaims beneficial ownership in the securities reported on this Form 4 except to the extent of its or his pecuniary interest, if any, therein, and this report shall not be deemed to be an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.

	Casdin Partners Master Fund, LP, By: Casdin Partners GP, LLC,, its General Partner, By: /s/ Eli Casdin, Managing Member	08/21/2025
	Casdin Capital LLC, By: /s/ Eli Casdin, Managing Member	08/21/2025
	Casdin Partners GP LLC, By: /s/ Eli Casdin, Managing Member	08/21/2025
	/s/ Eli Casdin, Eli Casdin	08/21/2025
	** 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.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction was reported for BLFS on this Form 4?

The filing reports a sale of 500,000 shares of BioLife Solutions, Inc. (BLFS) on 08/15/2025 at $24.40 per share.

How many BLFS shares did the reporting persons own after the transaction?

After the reported sale, the Master Fund beneficially owned 6,707,165 shares.

Which entities and individuals filed the Form 4 for BLFS?

The Form 4 was filed by Casdin Partners Master Fund, L.P., with related filings or disclosures for Casdin Capital, LLC, Casdin Partners GP, LLC, and Eli Casdin.

When were the signatures executed on the Form 4?

Signatures for the filing are dated 08/21/2025.

Does the Form 4 state who directly owns the reported securities?

Yes. The securities are owned directly by Casdin Partners Master Fund, L.P., and the filing explains indirect ownership by related entities and Eli Casdin.