[Form 4] BIOLIFE SOLUTIONS INC Insider Trading Activity

Rhea-AI Filing Summary

BioLife Solutions Inc. reported insider activity by Casdin-affiliated entities. Casdin Partners Master Fund, L.P. completed open-market sales totaling 1,200,000 shares of common stock over three days. The fund sold 300,000 shares at $22.65 on May 19, 2026, 250,000 shares at $23.70 on May 20, and 650,000 shares at $23.70 on May 21. After these sales, the Master Fund continued to hold 4,757,165 shares indirectly. According to the footnote, these securities are owned directly by the Master Fund and may be deemed indirectly beneficially owned by Casdin Capital, LLC, Casdin Partners GP, LLC, and Eli Casdin.

Insights

Equity analyst

Casdin-affiliated fund reported open-market sales but retains a large BLFS position.

Casdin Partners Master Fund, L.P., a ten percent owner of BioLife Solutions, reported three open-market sales totaling 1.2 million shares at prices between $22.65 and $23.70. These were straightforward stock disposals, not option exercises or tax-withholding events.

Following the transactions, the Master Fund still holds 4,757,165 shares indirectly. The filing notes that Casdin Capital, LLC, Casdin Partners GP, LLC, and Eli Casdin may be deemed indirect beneficial owners through their roles with the fund. The net activity is a 100% sell direction in this filing, but the remaining stake indicates ongoing exposure.

Insider Trade Summary

Net Seller: 1,200,000 shares ($28,125,000)

Net Sell 3 txns

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

Role null | null | null | null

Sold 1,200,000 shs ($28.13M)

Type	Security	Shares	Price	Value
Sale	Common Stock, par value $0.001 per share	650,000	$23.70	$15.40M
Sale	Common Stock, par value $0.001 per share	250,000	$23.70	$5.92M
Sale	Common Stock, par value $0.001 per share	300,000	$22.65	$6.79M

Holdings After Transaction: Common Stock, par value $0.001 per share — 4,757,165 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

X

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 NEW YORK 10019

(City) (State) (Zip)

UNITED STATES

(Country)

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)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/19/2026

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

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

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

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	05/19/2026		S		300,000	D	$22.65	5,657,165	I	See footnote(1)
Common Stock, par value $0.001 per share	05/20/2026		S		250,000	D	$23.7	5,407,165	I	See footnote(1)
Common Stock, par value $0.001 per share	05/21/2026		S		650,000	D	$23.7	4,757,165	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 NEW YORK 10019

(City) (State) (Zip)

UNITED STATES

(Country)

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 NEW YORK 10019

(City) (State) (Zip)

UNITED STATES

(Country)

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 NEW YORK 10019

(City) (State) (Zip)

UNITED STATES

(Country)

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 NEW YORK 10019

(City) (State) (Zip)

UNITED STATES

(Country)

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	05/21/2026
	Casdin Capital LLC, By: /s/ Eli Casdin, Managing Member	05/21/2026
	Casdin Partners GP LLC, By: /s/ Eli Casdin, Managing Member	05/21/2026
	/s/ Eli Casdin, Eli Casdin	05/21/2026
	** 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.
* Form 4: SEC 1474 (03-26)

FAQ

What insider sales did Casdin Partners Master Fund report for BioLife Solutions (BLFS)?

Casdin Partners Master Fund reported three open-market sales totaling 1,200,000 BioLife Solutions shares. The trades occurred on May 19, 20, and 21, 2026, disposing of blocks of 300,000, 250,000, and 650,000 shares of common stock, respectively, at prices around the mid-$20 range.

At what prices did Casdin Partners Master Fund sell its BioLife Solutions (BLFS) shares?

The fund sold BioLife Solutions shares between $22.65 and $23.70 per share. It sold 300,000 shares at $22.65 on May 19, 2026, then 250,000 and 650,000 shares at $23.70 on May 20 and May 21, reflecting consistent pricing across the larger trades.

How many BioLife Solutions (BLFS) shares does Casdin Partners Master Fund hold after these transactions?

After the reported sales, Casdin Partners Master Fund holds 4,757,165 BioLife Solutions shares indirectly. This remaining position, shown in the Form 4 as total shares following the last transaction, indicates the fund continues to maintain a sizeable stake in the company.

Who is considered the beneficial owner of the BioLife Solutions (BLFS) shares sold in this Form 4?

The securities are owned directly by Casdin Partners Master Fund, L.P. According to the footnote, they may be deemed indirectly beneficially owned by Casdin Capital, LLC as investment adviser, Casdin Partners GP, LLC as general partner, and Eli Casdin as managing member of those entities.

Does this BioLife Solutions (BLFS) Form 4 involve options or derivative securities?

No, all reported transactions involve non-derivative common stock. Each entry reflects an open-market sale of BioLife Solutions common stock, par value $0.001 per share, with no option exercises, conversions, or other derivative activities disclosed in the derivative summary section of the filing.

What is the overall direction of insider trading for BioLife Solutions (BLFS) in this Form 4?

The filing shows a net-sell direction totaling 1,200,000 shares. The transaction summary reports three sale transactions, no purchases or exercises, and net buy-sell shares of negative 1.2 million, all executed as open-market or private sale transactions by the reporting fund.