7. Convertible Promissory Note Receivable

On October 1, 2020, the Company entered into a master services agreement with Safi Biosolutions, Inc. (“Safi”). In addition, the Company invested $1.5 million in Safi in the form of a convertible promissory note (the "Note"). The Note bears interest at the rate of 5% per annum and is convertible into shares of Safi’s common stock (as defined). Principal and accrued interest mature on October 1, 2023.  For the years ended June 30, 2022 and 2021, interest income amounted to $75,000 and $56,000, respectively. As of June 30, 2022 and 2021, the Note balance and accrued interest totaled $1,631,000 and $1,556,000, respectively.