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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001344413-09-000003.txt : 20091026
<SEC-HEADER>0001344413-09-000003.hdr.sgml : 20091026
<ACCEPTANCE-DATETIME>20091026165221
ACCESSION NUMBER:		0001344413-09-000003
CONFORMED SUBMISSION TYPE:	D
PUBLIC DOCUMENT COUNT:		1
ITEM INFORMATION:		Rule 506
FILED AS OF DATE:		20091026
DATE AS OF CHANGE:		20091026
EFFECTIVENESS DATE:		20091026

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ARCA biopharma, Inc.
		CENTRAL INDEX KEY:			0000907654
		STANDARD INDUSTRIAL CLASSIFICATION:	IN VITRO & IN VIVO DIAGNOSTIC SUBSTANCES [2835]
		IRS NUMBER:				363855489
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		D
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	021-90765-4L
		FILM NUMBER:		091137304

	BUSINESS ADDRESS:	
		STREET 1:		8001 ARISTA PLACE
		STREET 2:		SUITE 200
		CITY:			BROOMFIELD
		STATE:			CO
		ZIP:			80021
		BUSINESS PHONE:		720-940-2200

	MAIL ADDRESS:	
		STREET 1:		8001 ARISTA PLACE
		STREET 2:		SUITE 200
		CITY:			BROOMFIELD
		STATE:			CO
		ZIP:			80021

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	NUVELO INC
		DATE OF NAME CHANGE:	20030203

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	HYSEQ INC
		DATE OF NAME CHANGE:	19970610
</SEC-HEADER>
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<SEQUENCE>1
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        <entityName>ARCA biopharma, Inc.</entityName>
        <issuerAddress>
            <street1>8001 ARISTA PLACE</street1>
            <street2>SUITE 200</street2>
            <city>BROOMFIELD</city>
            <stateOrCountry>CO</stateOrCountry>
            <zipCode>80021</zipCode>
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        <issuerPhoneNumber>720-940-2200</issuerPhoneNumber>
        <jurisdictionOfInc>DELAWARE</jurisdictionOfInc>
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            <previousName>NUVELO INC</previousName>
            <previousName>HYSEQ INC</previousName>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Michael</firstName>
                <middleName>R.</middleName>
                <lastName>Bristow</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>8001 Arista Place, Suite 200</street1>
                <city>Broomfield</city>
                <stateOrCountry>CO</stateOrCountry>
                <zipCode>80021</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Kathryn</firstName>
                <middleName>E.</middleName>
                <lastName>Falberg</lastName>
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                <street1>8001 Arista Place, Suite 200</street1>
                <city>Broomfield</city>
                <stateOrCountry>CO</stateOrCountry>
                <zipCode>80021</zipCode>
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            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Christopher</firstName>
                <middleName>D.</middleName>
                <lastName>Ozeroff</lastName>
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                <city>Broomfield</city>
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                <zipCode>80021</zipCode>
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                <firstName>Richard</firstName>
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                <city>Broomfield</city>
                <stateOrCountry>CO</stateOrCountry>
                <zipCode>80021</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Jean-Francois</firstName>
                <lastName>Formela</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>8001 Arista Place, Suite 200</street1>
                <city>Broomfield</city>
                <stateOrCountry>CO</stateOrCountry>
                <zipCode>80021</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
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            <relationshipClarification></relationshipClarification>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>J.</firstName>
                <middleName>William</middleName>
                <lastName>Freytag</lastName>
            </relatedPersonName>
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                <street1>8001 Arista Place, Suite 200</street1>
                <city>Broomfield</city>
                <stateOrCountry>CO</stateOrCountry>
                <zipCode>80021</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Linda</firstName>
                <lastName>Grais</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>8001 Arista Place, Suite 200</street1>
                <city>Broomfield</city>
                <stateOrCountry>CO</stateOrCountry>
                <zipCode>80021</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
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            <relationshipClarification></relationshipClarification>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Ted</firstName>
                <middleName>W.</middleName>
                <lastName>Love</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>8001 Arista Place, Suite 200</street1>
                <city>Broomfield</city>
                <stateOrCountry>CO</stateOrCountry>
                <zipCode>80021</zipCode>
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            <relatedPersonRelationshipList>
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            <relationshipClarification></relationshipClarification>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Mary</firstName>
                <middleName>K.</middleName>
                <lastName>Pendergast</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>8001 Arista Place, Suite 200</street1>
                <city>Broomfield</city>
                <stateOrCountry>CO</stateOrCountry>
                <zipCode>80021</zipCode>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Burton</firstName>
                <middleName>E.</middleName>
                <lastName>Sobel</lastName>
            </relatedPersonName>
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                <street1>8001 Arista Place, Suite 200</street1>
                <city>Broomfield</city>
                <stateOrCountry>CO</stateOrCountry>
                <zipCode>80021</zipCode>
            </relatedPersonAddress>
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            <relationshipClarification></relationshipClarification>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>John</firstName>
                <middleName>L.</middleName>
                <lastName>Zabriskie</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>8001 Arista Place, Suite 200</street1>
                <city>Broomfield</city>
                <stateOrCountry>CO</stateOrCountry>
                <zipCode>80021</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
    </relatedPersonsList>

    <offeringData>
        <industryGroup>
            <industryGroupType>Pharmaceuticals</industryGroupType>
        </industryGroup>
        <issuerSize>
            <revenueRange>Decline to Disclose</revenueRange>
        </issuerSize>
        <federalExemptionsExclusions>
            <item>06</item>
        </federalExemptionsExclusions>
        <typeOfFiling>
            <newOrAmendment>
                <isAmendment>false</isAmendment>
            </newOrAmendment>
            <dateOfFirstSale>
                <value>2009-10-18</value>
            </dateOfFirstSale>
        </typeOfFiling>
        <durationOfOffering>
            <moreThanOneYear>false</moreThanOneYear>
        </durationOfOffering>
        <typesOfSecuritiesOffered>
            <isEquityType>true</isEquityType>
            <isOptionToAcquireType>true</isOptionToAcquireType>
            <isSecurityToBeAcquiredType>true</isSecurityToBeAcquiredType>
        </typesOfSecuritiesOffered>
        <businessCombinationTransaction>
            <isBusinessCombinationTransaction>false</isBusinessCombinationTransaction>
            <clarificationOfResponse></clarificationOfResponse>
        </businessCombinationTransaction>
        <minimumInvestmentAccepted>0</minimumInvestmentAccepted>
        <salesCompensationList></salesCompensationList>
        <offeringSalesAmounts>
            <totalOfferingAmount>499999</totalOfferingAmount>
            <totalAmountSold>499999</totalAmountSold>
            <totalRemaining>0</totalRemaining>
            <clarificationOfResponse></clarificationOfResponse>
        </offeringSalesAmounts>
        <investors>
            <hasNonAccreditedInvestors>false</hasNonAccreditedInvestors>
            <totalNumberAlreadyInvested>1</totalNumberAlreadyInvested>
        </investors>
        <salesCommissionsFindersFees>
            <salesCommissions>
                <dollarAmount>0</dollarAmount>
            </salesCommissions>
            <findersFees>
                <dollarAmount>0</dollarAmount>
            </findersFees>
            <clarificationOfResponse></clarificationOfResponse>
        </salesCommissionsFindersFees>
        <useOfProceeds>
            <grossProceedsUsed>
                <dollarAmount>0</dollarAmount>
                <isEstimate>true</isEstimate>
            </grossProceedsUsed>
            <clarificationOfResponse></clarificationOfResponse>
        </useOfProceeds>
        <signatureBlock>
            <authorizedRepresentative>false</authorizedRepresentative>
            <signature>
                <issuerName>ARCA biopharma, Inc.</issuerName>
                <signatureName>/s/ Michael R. Bristow</signatureName>
                <nameOfSigner>Michael R. Bristow</nameOfSigner>
                <signatureTitle>President &amp; Chief Executive Officer</signatureTitle>
                <signatureDate>2009-10-26</signatureDate>
            </signature>
        </signatureBlock>
    </offeringData>
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