Revenue from contracts with customers is recognized when, or as, the Company satisfies its performance obligations by delivering the promised goods or service deliverables to the customers. A good or service deliverable is transferred to a customer when, or as, the customer obtains control of that good or service deliverable. A performance obligation may be satisfied over time or at a point in time. Revenue from a performance obligation satisfied over time is recognized by measuring the Company’s progress in satisfying the performance obligation in a manner that depicts the transfer of the goods or services to the customer. Revenue from a performance obligation satisfied at a point in time is recognized at the point in time that the Company determines the customer obtains control over the promised good or service deliverable. The amount of revenue recognized reflects the consideration the Company expects to be entitled to in exchange for those promised goods or services (i.e., the “transaction price”). In determining the transaction price, the Company considers multiple factors, including the effects of variable consideration. Variable consideration is included in the transaction price only to the extent it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainties with respect to the amount are resolved. In determining when to include variable consideration in the transaction price, the Company considers the range of possible outcomes, the predictive value of its past experiences, the time period of when uncertainties expect to be resolved and the amount of consideration that is susceptible to factors outside of the Company’s influence, such as the judgment and actions of third parties.

The Company had product and product-related services revenue consisting of revenue from the sale of instruments and consumables and the use of the HTG EdgeSeq proprietary technology to process samples and design custom RUO assays for the years ended December 31, 2021 and 2020 as follows:

	Years Ended December 31,
	2021		2020
Product revenue:
Instrument	$	1,385,665	$	869,035
Consumables		3,786,923		3,030,612
Total product revenue		5,172,588		3,899,647
Product-related services revenue:
Custom RUO assay design		48,350		1,393,316
RUO sample processing		3,685,890		2,597,891
Total product-related services revenue		3,734,240		3,991,207
Total product and product-related services revenue	$	8,906,828	$	7,890,854

As the Company’s agreements for product and product-related services revenue have an expected duration of one year or less, the Company has elected the practical expedient in ASC 606-10-50-14(a) to not disclose information about its remaining performance obligations.

The delivery of each instrument and related installation and calibration are considered to be a single performance obligation, as the HTG EdgeSeq instrument must be professionally installed and calibrated prior to use. Instrument product revenue is generally recognized upon installation and calibration of the instrument by field service engineers, which represents the point at which the customer has the ability to use the instrument and has accepted the asset. Installation generally occurs within one month of instrument shipment.

The delivery of each consumable is a separate performance obligation. Consumables revenue is recognized upon transfer of control, which represents the point when the customer has legal title and the significant risks of ownership of the asset. The Company’s standard terms and conditions provide that no right of return exists for instruments and consumables, unless replacement is necessary due to delivery of defective or damaged product. Customer payment terms vary but are typically between 30 and 90 days of revenue being earned from shipment or delivery, as applicable.

Shipping and handling fees charged to the Company’s customers for instruments and consumables shipped are included in the consolidated statements of operations as part of product and product-related services revenue. Shipping and handling costs for sold products shipped to the Company’s customers are included in the consolidated statements of operations as part of cost of product and product-related services revenue.

For sales of consumables in the United States, standard delivery terms are FOB shipping point, unless otherwise specified in the customer contract, reflecting transfer of control to the customer upon shipment. Standard delivery terms for sales to customers outside of the United States are FOB delivery point, unless otherwise specified in the customer contract. The Company has elected the practical expedient to account for shipping and handling as activities to fulfill the promise to transfer the consumables.

The Company provides instruments to certain customers under reagent rental agreements. Under these agreements, the Company installs instruments in the customer’s facility without a fee and the customer agrees to purchase consumable products at a stated price over the term of the agreement; in some instances, the agreements do not contain a minimum purchase requirement. Terms range from several months to multiple years and may automatically renew in several month or multiple year increments unless either party notifies the other in advance that the agreement will not renew. The Company measures progress toward complete satisfaction of this performance obligation to provide the instrument and deliver the consumables using an output method based on the number of consumables delivered in relation to the total consumables to be provided under the reagent rental agreement. This is considered to be representative of the delivery of outputs under the arrangement and the best measure of progress because the customer benefits from the instrument only in conjunction with the consumables. The Company expects to recover the cost of the instrument under the agreement through the fees charged for consumables, to the extent sold, over the term of the agreement.

In reagent rental agreements, the Company retains title to the instrument and title is transferred to the customer at no additional charge at the conclusion of the initial arrangement. The cost of the instrument is amortized on a straight-line basis over the term of the arrangement, unless there is no minimum consumable product purchase, in which case the instrument would be expensed as cost of product and product-related services revenue upon installation. Cost to maintain the instrument while title remains with the Company is charged to selling, general and administrative expense as incurred.

The Company also provides sample preparation and processing services and molecular profiling of retrospective cohorts for its customers through its VERI/O laboratory, whereby the customer provides samples to be processed using HTG EdgeSeq technology specified in the order. Customers are charged a per sample fee for sample processing services which is recognized as revenue upon delivery of a data file to the customer showing the results of testing and completing delivery of the agreed upon service. This is when the customer can use and benefit from the results of testing and the Company has the present right to payment.

The Company enters into custom RUO assay design agreements that may generate up-front fees and subsequent payments that might be earned upon completion of design process phases. The Company measures progress toward complete satisfaction of its performance obligation to perform custom RUO assay design using an output method based on the costs incurred to date compared with total expected costs, as this is representative of the delivery of outputs under the arrangements and the best measure of progress. However, because in most instances the assay development fees are contingent upon completion of each phase of the design project and the decision of the customer to proceed to the next phase, the amount to be included in the transaction price and recognized as revenue is limited to that which the customer is contractually obligated to pay upon completion of that phase, which is when it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur. Changes in estimates of total expected costs are accounted for prospectively as a change in estimate. From period to period, custom RUO assay design service revenue can fluctuate substantially based on the completion of design-related phases.

The Company did not recognize any custom RUO assay design revenue from performance obligations that were satisfied in previous periods during the years ended December 31, 2021 and 2020.

The Company enters into collaborative development services agreements with biopharmaceutical companies for the development of NGS-based companion diagnostic assays in support of and in conjunction with, biopharmaceutical companies’ drug development programs. These collaborative development services agreements may generate upfront fees, and in some cases subsequent milestone payments that may be earned upon completion of certain product development milestones or activities. The Company follows ASC 606 and ASC 808 to determine the appropriate recognition of revenue under its collaborative research, development and commercialization agreements. For the year ended December 31, 2020, collaborative development services revenue was generated through statements of work entered into under a Master Assay Development, Commercialization and Manufacturing Agreement (the “Governing Agreement”) with QIAGEN Manchester Limited (“QML”) discussed below.

The Governing Agreement created the framework for QML and the Company to combine their technological and commercial strengths to offer biopharmaceutical companies a complete NGS-based solution for the development, manufacture and commercialization of companion diagnostic assays. Under the Governing Agreement, the parties jointly sought companion diagnostic programs with biopharmaceutical companies, with QML entering into sponsor project agreements with interested biopharmaceutical companies for specified projects, and QML and the Company entering into statements of work which set forth the rights and obligations of QML and the Company with respect to each project. In November 2019, the Company elected to terminate the Governing Agreement with QML. The Company’s termination of the Governing Agreement did not terminate active statements of work under the Governing Agreement. Remaining agreed upon procedures associated with these statements of work were completed in the prior year and no additional collaborative development services programs have been entered into as of December 31, 2021.

Because each SOW has an expected duration of one year or less, the Company has elected the practical expedient in ASC 606-10-50-14(a) to not disclose information about its remaining performance obligations for each SOW.

The Company may receive up-front payments from customers for custom RUO assay design and sample processing services. In addition, payments for instrument extended warranty contracts are required to be made in advance. The Company recognizes such up-front payments as contract liabilities. The contract liabilities are subsequently reduced at the point in time that the data files are delivered for sample processing services or as the Company satisfies its performance obligations over time for RUO assay design and extended warranty services. Contract liabilities of $0.1 million were included in contract liabilities – current and an additional immaterial amount of contract liabilities were included in other non-current liabilities in the consolidated balance sheets as of December 31, 2021, reflecting the period in which the Company expects to realize the deferred revenue.

Changes in the Company’s contract liabilities were as follows as of the dates indicated:

	Product Revenue			Custom RUO Assay Design		Sample Processing			Total Contract Liability
Balance at January 1, 2021	$	103,580		$	-	$	93,884		$	197,464
Deferral of revenue		286,349			-		587,091			873,440
Recognition of deferred revenue		(261,400	)		-		(650,354	)		(911,754	)
Balance at December 31, 2021	$	128,529		$	—	$	30,621		$	159,150

	Product Revenue			Custom RUO Assay Design			Sample Processing			Total Contract Liability
Balance at January 1, 2020	$	95,148		$	66,216		$	438,090		$	599,454
Deferral of revenue		500,045			566,733			124,404			1,191,182
Recognition of deferred revenue		(491,613	)		(632,949	)		(186,888	)		(1,311,450	)
Transfer to refund liability		—			—			(281,722	)		(281,722	)
Balance at December 31, 2020	$	103,580		$	—		$	93,884		$	197,464