-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 RYDNJrAYPeOwBb4yeacFTDUw5DTTS5K0rFyR5j5fSUzZkpIFKkFyhVHDB/3lWMUo
 c91gE1hWp8TfUVvKQDqhmg==

<SEC-DOCUMENT>0001293818-10-000003.txt : 20100510
<SEC-HEADER>0001293818-10-000003.hdr.sgml : 20100510
<ACCEPTANCE-DATETIME>20100510122703
ACCESSION NUMBER:		0001293818-10-000003
CONFORMED SUBMISSION TYPE:	D/A
PUBLIC DOCUMENT COUNT:		1
ITEM INFORMATION:		Rule 506
FILED AS OF DATE:		20100510
DATE AS OF CHANGE:		20100510
EFFECTIVENESS DATE:		20100510

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			OPGEN INC
		CENTRAL INDEX KEY:			0001293818
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		D/A
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	021-66404
		FILM NUMBER:		10815109

	BUSINESS ADDRESS:	
		STREET 1:		708 QUINCE ORCHARD ROAD
		CITY:			GAITHERSBURY
		STATE:			MD
		ZIP:			20878
		BUSINESS PHONE:		240-813-1273

	MAIL ADDRESS:	
		STREET 1:		708 QUINCE ORCHARD ROAD
		CITY:			GAITHERSBURY
		STATE:			MD
		ZIP:			20878
</SEC-HEADER>
<DOCUMENT>
<TYPE>D/A
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<edgarSubmission>

    <schemaVersion>X0704</schemaVersion>

    <submissionType>D/A</submissionType>

    <testOrLive>LIVE</testOrLive>

    <primaryIssuer>
        <cik>0001293818</cik>
        <entityName>OPGEN INC</entityName>
        <issuerAddress>
            <street1>708 QUINCE ORCHARD ROAD</street1>
            <city>Gaithersburg</city>
            <stateOrCountry>MD</stateOrCountry>
            <stateOrCountryDescription>MARYLAND</stateOrCountryDescription>
            <zipCode>20878</zipCode>
        </issuerAddress>
        <issuerPhoneNumber>240-813-1273</issuerPhoneNumber>
        <jurisdictionOfInc>DELAWARE</jurisdictionOfInc>
        <issuerPreviousNameList>
            <value>None</value>
        </issuerPreviousNameList>
        <edgarPreviousNameList>
            <value>None</value>
        </edgarPreviousNameList>
        <entityType>Corporation</entityType>
        <yearOfInc>
            <overFiveYears>true</overFiveYears>
        </yearOfInc>
    </primaryIssuer>

    <relatedPersonsList>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Ronald</firstName>
                <middleName>W.</middleName>
                <lastName>Lennox</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>708 Quince Orchard Road</street1>
                <city>Gaithersburg</city>
                <stateOrCountry>MD</stateOrCountry>
                <stateOrCountryDescription>MARYLAND</stateOrCountryDescription>
                <zipCode>20878</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Corey</firstName>
                <lastName>Mulloy</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>708 Quince Orchard Road</street1>
                <city>Gaithersburg</city>
                <stateOrCountry>MD</stateOrCountry>
                <stateOrCountryDescription>MARYLAND</stateOrCountryDescription>
                <zipCode>20878</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Bijan</firstName>
                <lastName>Salehizadeh</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>708 Quince Orchard Road</street1>
                <city>Gaithersburg</city>
                <stateOrCountry>MD</stateOrCountry>
                <stateOrCountryDescription>MARYLAND</stateOrCountryDescription>
                <zipCode>20878</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Brian</firstName>
                <middleName>G.</middleName>
                <lastName>Atwood</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>708 Quince Orchard Road</street1>
                <city>Gaithersburg</city>
                <stateOrCountry>MD</stateOrCountry>
                <stateOrCountryDescription>MARYLAND</stateOrCountryDescription>
                <zipCode>20878</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Evan</firstName>
                <lastName>Jones</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>708 Quince Orchard Road</street1>
                <city>Gaithersburg</city>
                <stateOrCountry>MD</stateOrCountry>
                <stateOrCountryDescription>MARYLAND</stateOrCountryDescription>
                <zipCode>20878</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>C. Eric</firstName>
                <lastName>Winzer</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>708 Quince Orchard Road</street1>
                <city>Gaithersburg</city>
                <stateOrCountry>MD</stateOrCountry>
                <stateOrCountryDescription>MARYLAND</stateOrCountryDescription>
                <zipCode>20878</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
    </relatedPersonsList>

    <offeringData>
        <industryGroup>
            <industryGroupType>Biotechnology</industryGroupType>
        </industryGroup>
        <issuerSize>
            <revenueRange>Decline to Disclose</revenueRange>
        </issuerSize>
        <federalExemptionsExclusions>
            <item>06</item>
        </federalExemptionsExclusions>
        <typeOfFiling>
            <newOrAmendment>
                <isAmendment>true</isAmendment>
                <previousAccessionNumber>0001293818-10-000002</previousAccessionNumber>
            </newOrAmendment>
            <dateOfFirstSale>
                <value>2010-03-23</value>
            </dateOfFirstSale>
        </typeOfFiling>
        <durationOfOffering>
            <moreThanOneYear>false</moreThanOneYear>
        </durationOfOffering>
        <typesOfSecuritiesOffered>
            <isDebtType>true</isDebtType>
            <isOptionToAcquireType>true</isOptionToAcquireType>
        </typesOfSecuritiesOffered>
        <businessCombinationTransaction>
            <isBusinessCombinationTransaction>false</isBusinessCombinationTransaction>
            <clarificationOfResponse></clarificationOfResponse>
        </businessCombinationTransaction>
        <minimumInvestmentAccepted>0</minimumInvestmentAccepted>
        <salesCompensationList></salesCompensationList>
        <offeringSalesAmounts>
            <totalOfferingAmount>8186000</totalOfferingAmount>
            <totalAmountSold>4018522</totalAmountSold>
            <totalRemaining>4167478</totalRemaining>
            <clarificationOfResponse></clarificationOfResponse>
        </offeringSalesAmounts>
        <investors>
            <hasNonAccreditedInvestors>false</hasNonAccreditedInvestors>
            <totalNumberAlreadyInvested>13</totalNumberAlreadyInvested>
        </investors>
        <salesCommissionsFindersFees>
            <salesCommissions>
                <dollarAmount>0</dollarAmount>
            </salesCommissions>
            <findersFees>
                <dollarAmount>0</dollarAmount>
            </findersFees>
            <clarificationOfResponse></clarificationOfResponse>
        </salesCommissionsFindersFees>
        <useOfProceeds>
            <grossProceedsUsed>
                <dollarAmount>0</dollarAmount>
            </grossProceedsUsed>
            <clarificationOfResponse></clarificationOfResponse>
        </useOfProceeds>
        <signatureBlock>
            <authorizedRepresentative>false</authorizedRepresentative>
            <signature>
                <issuerName>OPGEN INC</issuerName>
                <signatureName>/s/ C. Eric Winzer</signatureName>
                <nameOfSigner>C. Eric Winzer</nameOfSigner>
                <signatureTitle>Chief Financial Officer</signatureTitle>
                <signatureDate>2010-05-07</signatureDate>
            </signature>
        </signatureBlock>
    </offeringData>
</edgarSubmission>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----