Revenue Recognition Policy prior to the adoption of new revenue recognition guidelines on January 1, 2018 The Company recognized revenues when persuasive evidence of an arrangement existed, delivery had occurred or services had been provided, the purchase price was fixed or determinable and collectability reasonably assured. The Companys historical revenue was generated pursuant to cost reimbursable federal grants and pursuant to joint development arrangements. For cost reimbursable grants, revenues were based on internal and subcontractor costs incurred that are specifically covered under reimbursement arrangements, and where applicable, an additional facilities and administrative rate that provides funding for overhead expenses. Grant revenue was recognized as grant-related expenses were incurred by the Company or its subcontractors. The grant agreements with federal government agencies generally provide that, upon completion of a technology development program, the funding agency is granted a royalty-free license to use any technology developed during the course of the program for its own purposes, but not any preexisting technology that the Company uses in connection with the program. The Company retains all other rights to use, develop, and commercialize the technology. For joint development arrangements, revenue was recognized when the related expenditure was made under the reimbursement provisions of the sponsored research agreement or activities under a patent license agreement, or when the Companys obligations under the arrangements were completed. Policy after the adoption of new revenue recognition guidelines on January 1, 2018 On January 1, 2018, the Company adopted Topic 606, Revenue from Contracts with Customer using the modified retrospective method applied to those contracts which were not completed as of January 1, 2018. The Company analyzes contracts to determine the appropriate revenue recognition using the following steps: (i) identification of contracts with customers; (ii) identification of distinct performance obligations in the contract; (iii) determination of contract transaction price; (iv) allocation of contract transaction price to the performance obligations; and (v) determination of revenue recognition based on timing of satisfaction of the performance obligation. The Company recognizes revenues upon the satisfaction of its performance obligations (upon transfer of control of promised goods or services to customers) in an amount that reflects the consideration to which it expects to be entitled to in exchange for those goods or services. Deferred revenue results from cash receipts from or amounts billed to customers in advance of the transfer of control of the promised services to the customer and is recognized as performance obligations are satisfied. When sales commissions or other costs to obtain contracts with customers are considered incremental and recoverable, those costs are deferred and then amortized as selling and marketing expenses on a straight-line basis over an estimated period of benefit. The Company determined that its sole revenue arrangement as of the date of adoption, a cost-reimbursable federal grant with the National Institutes of Health, is not within the scope of the new revenue guidance and, accordingly, the Company will continue to recognize revenue on this grant as grant-related expenses are incurred by the Company or its subcontractors. As such, the adoption did not impact the Companys consolidated financial statements. The Company recognized $216,530 and $62,259 of revenue under cost-reimbursable grants during the three months ended September 30, 2018 and 2017, respectively. The Company recognized $465,446 and $438,210 of revenue under cost-reimbursable grants during the nine months ended September 30, 2018 and 2017, respectively. The Company also determined that it has not incurred incremental costs to obtain contracts with customers or material costs to fulfill contracts with customers and did not have any material contract assets or liabilities as of September 30, 2018.