• evo视讯(中国)

    IgG sequencing of rat hybridoma

    Tamer B Shabaneh

    Published: 2023-08-21 DOI: 10.17504/protocols.io.x54v9ppw1g3e/v1
    AI 解读
    浏览 1396

    Abstract

    The purpose of this protocol is to amplify IgG antibody variable regions derived from rat hybridoma RNA, using RT-PCR and Sanger sequencing.

    Materials needed:

    •    RNA extraction: Qiagen RNEasy mini kit (74104)
      

    -        Reverse Transcription Kit: SMARTScribe Reverse Transcriptase (639537)

    -        DNA Polymerase: Invitrogen Platinum SuperFi II PCR Master Mix (12368010)

    •    Invitrogen's PureLink™ PCR Purification Kit \#K310001
      

    The layout of this protocol was adapted from a protocol composed by Andrew McGuire's laboratory at the Fred Hutchinson Cancer Center, which in turn was adapted from Meyer et al 2019 "A simplified workflow for monoclonal antibody sequencing." See attachment for the respective manuscript.

    For this protocol, rat-specific primers were designed, as the immunization campaign was executed in rats. See attachment for the primer design strategy.

    Attachments

    Meyer et al 2019 A simplified workflow for monoclonal antibody sequencing.pdf 20211119 primer design.xlsx

    Steps

    Primers

    1.

    TS pF is ordered as RNA oligo; the remainder as DNA oligo

    universal TS pF AAGCAGTGGTATCAACGCAGAGTACATrGrGrG

    ISPCR pF aagcagtggtatcaacgcagag

    rat IGHG RT pR GGACAGGGCTCCAGAGTTCC

    rat IGHG PCR pR GACTGGCTCAGGGAAATAGCC

    rat IGKC RT pR CTGATCAGTAACACTGTCCAGGAC

    rat IGKC PCR pR CACTGATGTCTCTGGGATAGAAGTTG

    rat IGLC1 RT pR GGGAGATAGGTGCACCATTTGC

    rat IGLC1 PCR pR GGCCACTTCCACATCACTCG

    rat IGLC2 RT pR TCCACACCCTGAGTGATAGGG

    rat IGLC2 PCR pR CTTCCAGACCACTGTCATAACACC

    Procedure

    2.

    RNA extraction: Extract RNA from the hybridoma sample using RNeasy total RNA kit, according to the manufacturer’s instructions.

    3.

    Reverse Transcription: On ice, prepare the 1st reaction mix in PCR tubes for gamma chain and kappa chain (or lambda chain) cDNA synthesis according to the following recipe:

    3.1.

    Gamma

    AB
    ComponentVolume per rxn
    IGHG RT pR (10 uM)1 uL
    dNTP (10 mM)1 uL
    RNA sample (50 ng/uL)2 uL
    Total volume4 uL
    3.2.

    Kappa

    AB
    ComponentVolume per rxn
    IGKC RT pR (10 uM)1 uL
    dNTP (10 mM)1 uL
    RNA sample (50 ng/uL)2 uL
    Total volume4 uL
    3.3.

    Lambda (include later if Kappa does not amplify)

    AB
    ComponentVolume per rxn
    IGLC1 (or C2) RT pR (10 uM)1 uL
    dNTP (10 mM)1 uL
    RNA sample (50 ng/uL)2 uL
    Total volume4 uL
    3.4.

    On ice, prepare a 2nd mastermix in Eppendorf tubes. This recipe if for one reaction regardless of chain type.  Scale up for the number of samples as needed.

    2nd reaction mix nd reaction mix

    AB
    ComponentVolume per rxn
    5x SMARTScribe buffer2 uL
    DTT (20 mM)1 uL
    Universal TS pR (100 uM)0.3 uL
    H2O1.70 uL
    Total volume5.00 uL
    3.5.

    After preparing the 2nd mastermix, incubate each of the 1st reaction mixes in a thermocycler for  3 minutes at 72°C.

    3.6.

    While the incubation reaction is proceeding, add the following to the 2nd reaction mix:

    AB
    ComponentVol. per rxn
    RNAse inhibitor (40 U/uL)0.50 uL
    SMARTScribe Rev. Transcriptase (100 U/uL)0.50 uL
    Total volume1.00 uL
    3.7.

    Once the incubation of the 1st reaction mix (from step 3.5) finishes, add 6 uL of the 2nd reaction mix to each tube of the 1st reaction mix.

    3.8.

    With the 2 reaction mixes now combined, incubate each according to the following conditions:

    ABC
    TemperatureTimeCycles
    42°C60 min1
    70°C5 min1
    4°Chold-

    Proceed to PCR amplification step immediately after incubation has finished (once samples reach 4°C hold step).

    4.

    PCR amplification: Prepare mastermix for PCR reaction according to following 2-step recipe:

    4.1.

    Add the following components to each PCR tube.

    Gamma

    AB
    ComponentVolume per rxn
    Platinum SuperFi II PCR MM25 uL
    ISPCR pF (10 uM)2.5 uL
    IGHG PCR pR (10 uM)2.5 uL
    cDNA from RT step (5-100ng)3 uL
    Water, nuclease-free17 uL
    Total volume50 uL
    4.2.

    Kappa

    AB
    ComponentVolume per rxn
    Platinum SuperFi II PCR MM25 uL
    ISPCR pF (10 uM)2.5 uL
    IGK PCR pR (10 uM)2.5 uL
    cDNA from RT step (5-100ng)3 uL
    Water, nuclease-free17 uL
    Total volume50 uL
    4.3.

    Lambda (if Kappa doesn’t amplify)

    AB
    ComponentVolume per rxn
    Platinum SuperFi II PCR MM25 uL
    ISPCR pF (10 uM)2.5 uL
    IGLC1 (or C2) PCR pR (10 uM)2.5 uL
    cDNA from RT step (5-100ng)3 uL
    Water, nuclease-free17 uL
    Total volume50 uL
    4.4.

    Cap each tube, then mix and briefly centrifuge the PCR tubes.

    Place PCR tubes in thermocycler, and run according to the following conditions:

    Gamma

    ABC
    TemperatureTimeCycles
    98°C30 sec1
    98°C15 sec35
    63°C30 sec 
    72°C25 sec 
    72°C5 min1
    4°Chold-

    Kappa/Lambda

    ABC
    TemperatureTimeCycles
    98°C30 sec1
    98°C15 sec35
    56°C30 sec 
    72°C25 sec 
    72°C5 min1
    4°Chold-
    5.

    Verify the gel bands

    After PCR reaction completes, set up 1% agarose gel according to the following conditions:

    In a flask, add the following components:

    0.5 g – Agarose powder

    50 mL – 1X TAE buffer

    Put flask, with added reagents, in microwave and heat up until all the powder is fully dissolved (about 1 minute).

    After microwaving is finished, remove flask with hot pad; add 5 uL of Sybrsafe to flask, swirl to mix. Pour into a tray with appropriate plastic comb, preferably one with wells that accommodate 20uL volumes.

    Prepare a fraction of each PCR products to verify the band size on the gel. Aliquot 5 uL from each PCR tube into a new PCR strip, and add 1 uL of DNA Loading Dye to each sample.

    Load the gel and run it for 25-30 minutes at 110 V.  Modify these settings if needed.

    Remove gel, image, and save an image copy for the records.

    Note:  There should be a gamma chain, and either a kappa or lambda chain.

    Amplified rat antibody products: 550-600 bp.

    A significant majority of mouse antibody light chains will be kappa; if kappa not present, repeat with IGLC1 and IGLC2 samples.

    6.

    PCR cleanup

    PCR samples that produce a band of the expected size can then be finalized using a PCR purification kit (e.g. Invitrogen's PureLink™ PCR Purification Kit #K310001), and eluted in 25 uL volume. Verify cDNA concentration by nanodrop.

    7.

    Sanger sequencing should be performed (e.g. GeneWiz or Genomic Core).

    8.

    Analyze the antibody nucleotide sequence

    Open the website: http://www.imgt.org/IMGT_vquest/vquest

    Copy and paste sequence into the IMGT webpage, in the section “sequence submission”.

    Select “Rattus norvergicus” for species, and “IGH” as receptor type or locus.

    Click on "Start".

    推荐阅读

    Nature Protocols
    Protocols IO
    Current Protocols
    扫码咨询