August 2020

Investor Presentation

Safe Harbor

This presentation contains forward looking statements which are made pursuant to the safe harbor provisions of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. These statements are subject to risks and uncertainties which may cause our plans to change or actual results to differ materially from those anticipated. In particular, unforeseen events outside of our control may adversely impact future results. Additional information concerning these factors is discussed in our reports filed with the Securities and Exchange Commission including recent Form 8-Ks, our most recent Annual Report on Form 10K and our most recent Quarterly Reports on Form 10Q. The forward looking statements in this presentation reflect management’s current views and may become obsolete as a result of new information, future events or otherwise. We may not update such forward looking statements to reflect a change of events or circumstances that occur after the date hereof, except as required by law. The industry and market data contained in this presentation are based on management’s own estimates, independent publications, government publications, reports by market research firms or other published independent sources, and, in each case, are believed by management to be reasonable estimates. Although we believe these sources are reliable, we have not independently verified the information.

2

Repligen Overview

Advancing innovation as a trusted partner in the production

of biologic drugs

Repligen Snapshot

Bioprocessing innovator with

diversified portfolio

Enabling efficient, single-use,

high productivity manufacturing

Differentiated, disruptive products

with high brand recognition

Accelerating demand from

gene therapy and COVID-19 programs

Supported by a robust and

expanding global biologics market>760

EMPLOYEESfrom ~550 at YE 2018REVENUE SPLITS

FY 2019

44%

24%

24%Filtration

Chroma

Proteins

GeneTherapy

85%

15%

mAbsrProteinsvaccines

GeneTherapy

4

33%Organic Growth

FY 2019

$270.2MTOTAL REVENUE

57%GROSS MARGIN

FY 2019

39%RevenueGrowth

26%ADJ. EBITDA MARGIN

FY 2019

>1,000 EMPLOYEES

23%-26%Revenue Growth18%-21% Organic

Guide 2020*

$332-$340MTOTAL REVENUE

56.5%-57%GROSS MARGIN

FY 2020

27%ADJ. EBITDA MARGIN

FY 2020

*as of 7/30/20 earnings call; see appendix for GAAP to non-GAAP reconciliations

Market Drivers, Addressable Markets

Strong End Markets for Bioprocessing

1. Antibodies to Watch in 2019 MAbs. 2019 Feb/Mar 11(2)219-238 PubMed link, FDA.gov2. Alliance for Regenerative Medicine Q3 2019 report ARM report , FDA.gov; Includes gene therapy and gene-modified cell therapy3. SDI Bioprocessing Market Analysis and Perspectives Sept. 2018

Monoclonal Antibodies (mAbs)1

110FDAapprovedYE 2019 >550

clinical trials

Gene and Cell Therapy

8FDAapprovedYE 2019 >1,000

clinical trials

• Originator and biosimilar mAbs, emerging gene therapy driving growth

• >750 gene therapy clinical trials2;90% in Phase 1 and Phase 2 trials

• 2019-2023 estimates for gene therapy market growth; 20%-30% CAGR

Surging clinical activity driving major capacity expansion

2019 bioprocessing market

8%-10%CAGR thru 20223

~$10B

6

Robust market for bioprocessing technology and expertise

Urgent Clinical Programs Targeting COVID-19

Source: WCG Knowledge Base: wcgclinica.com/covid-19/#dashboard

Sudden and critical need driving additional demand for Repligen products

7

Focus is on Vaccines to halt spread of virus

Select vaccines and therapeutics in clinical trials(not necessarily involving Repligen products)

Viral vector;AZD1222

Inactivated; CoronaVac

Repligen Rapid Response

• Traction with existing customers

• COVID-related demand 2020 (est.):

• >$15M in COVID-related revenue

• ~5% of revenue

• 40%-50% of order growth

• Filtration, Chromatography, Proteins

Source: PhRMA phrma.org/coronavirus/activity-tracker as of 08/11/2020

Sources: World Health Organization 07/31/20 publication who.int; RAPS https://www.raps.org/news-and-articles/news-articles/2020/3/covid-19-therapeutics-tracker

Remdesivirapproved for emergency use

mAb cocktail;REGN CoV2

mAb;LY-CoV555

mAb;lenzilumab

mAb;ravulizumab

mAb;canakinumab

MRNA;BNT162

Viral vector;Ad5-nCoV

Inactivated

MRNA;mRNA-1273

mAb;gimsilumab

Synth DNA;INO-4800

Filtration*10%+ share2019 organic growth >30% Leader in upstream clarification Taking share downstream (UF/DF)

Our Total Addressable Market

Proteins~10% market share 2019 organic growth >20%Ligands organic growth ~15%Leader in Protein A ligands

Chromatography20%+ share2019 organic growth >40%Leader in pre-packed columns (PPC)

Winning market share with differentiated technology

Process Analytics5%+ sharePro-forma 2019 growth ~10%Leader in protein concentration measurement

~$500M

~$500M

~$1.6B

~$550M

~$500M ~$325M

~$3.0BTAM

8

*includes Engineered Molding Technology TAM $200M, acquired July 31, 2020

Our Performance

24%

44%

24%

6%2%

$60.4

$83.5

$104.4

$141.1

$193.9

$270.2

$336.0

$0.24

$0.44$0.49

$0.69

$0.73

$1.07

$1.27

$0.00

$0.10

$0.20

$0.30

$0.40

$0.50

$0.60

$0.70

$0.80

$0.90

$1.00

$1.10

$1.20

$1.30

$0

$40

$80

$120

$160

$200

$240

$280

$320

$360

FY 14 FY 15 FY 16 FY 17 FY 18 FY 19* FY 20 G

midpt

Track Record of Execution and Performance

Disruptive technologies driving diversification … and increased revenue and profitability

*Change in accounting for the treatment of tax on certain intangible amortization in 2019; adj. EPS figures for prior periods do not reflect this change** Non-GAAP financial measure; see reconciliation tables in appendix** Guidance as of 7/30/2020 earnings call; see reconciliation tables in appendix

Proteins (OEM) Filtration (Direct) Chromatography (Direct)

~35%5-year

Revenue CAGR72%11%

16%1%

2014

2018

28%

47%

23%

2%

72%DIRECT

2019

10

Rev

enu

e (i

n $

Ms)

Ad

j. EPS fu

lly dilu

ted **

>4xincrease in

Adj. EPS

76%DIRECT

28%DIRECT

Process Analytics) Other

2014-2019

Our Blueprint for Growth

Accelerate growth through disciplined M&A and R&D

Transform bioprocessing through high-impact technology innovation

Enter new markets and expand applications

Scale to meet demand

Position portfolio for future growth in biologics markets; mAbs, recombinant proteins, gene therapy

Deliver results and create value for customers and shareholders

M&A2014-2019

5ACQUISITIONS

~40% CUMULATIVE REVENUE

represented by acquisitions2014-2019

6YEARS

R&D2014-2019

12NEXT-GENERATION

PRODUCTSthru R&D

11

Accelerating Growth through M&A and R&D

Accelerating Growth through Acquisitions

* Excluding $4M in sales to Repligen** Revenue Growth, first full year of Repligen ownership (proforma)

JUNE 2014 APRIL 2016 DEC. 2016 AUG. 2017

Filtration leadership inperfusion; XCell™ ATF

Key Benefit Entry point for PPC in process development;

OPUS® PD

Downstream single-usefiltration; SIUS™ TFF

Hollow fiber filtration and system portfolio;

KrosFlo™ TFFSales force Asia

MAY 2019

Establishes analytics franchise; at-line and

real-time measurement

PF Revenue $10.6M $4.6M $5.8M $37M* ~$24M

48% 26% 37% 24% >30% est.Year 1 Growth**

1 2 3 4 5

13

Engineered Molding Technology: Acquisition #6

14

Tuck-in acquisition, closed July 13, 2020, meets our M&A criteria

Adds ~$3.5M to $4.0M of incremental revenue in 2020E (6 months); adds $200M to TAM

Gross margins and operating margins in line with Repligen corporate average with path to margin expansion following initial investment

Accretive to adjusted EPS for 2021E and thereafter

Addresses requirement for leakproof assemblies in biologics manufacturing

Underinvested in commercial with opportunity to build on OEM and Direct customer base and strengthen Repligen offering

Expands single-use presence and establishes core competency in silicone extrusion and over-molding technology

Engineered Molding Technology

15

Headquarters: Clifton Park, NY

Founded: 2010

Co-founders: Mike Pandori & Todd Etesse

Employees: 50

Sales offices: U.S.

Distributors: NA, EU

Rev

enu

e (

$M

s)

$0.0

$1.0

$2.0

$3.0

$4.0

$5.0

$6.0

$7.0

$8.0

$9.0

2017 2018 2019 2020

>30%Revenue CAGR

2017-2020e

Molded connections

Tubeset with over-molded fittings

Experts in molding and over-molded components and sub-assemblies

Reputation for customization, reliability, industry-leading turnaround

Revenue Sources• ~90% OEM

Bioprocess customers, including Repligen

• ~10% Direct Biopharma and CDMO customers

Qualified by key industry players

Transforming Bioprocessing

High Performance

Affinity Ligands

Bringing Industry “Firsts” to Market

Single-use KrosFlo® Integrated TFF Skids

Establishing Key Partnerships to Expand Market Position

Next-generation Protein A ligands

Integrated perfusion

bioreactors

Focused on High Impact Technology Innovation

OPUS® R Pre-packed Columns

Single-use TangenX™ Flat Sheet TFF

Single-use XCell™ ATF Perfusion Systems

16

Advancing Growth through R&DTransformative high-impact “industry firsts”

Filtration

ChromaProcess

AnalyticsProteins

Single-use ATF™ perfusion with multiplex controller

OPUS® pre-packed columnsCustomer choice of resin & bed height;Resin recovery feature

SoloVPE and FlowVPEAt-line and in-line protein concentration measurement

NGL-Impact® AHigh-performance Pr A ligand;Reduces cost and improves process economics

TangenX™ SIUS™ single-use TFF;Incl. gamma-irradiated SIUS™High performance with lower cost

TFDF™ disruptive technology Displaces centrifugation in fed-batch clarification

KrosFlo® systems“Plug and play” functionality in both upstream and downstream

17

Expanding Capacity

Global Commercial

YE 2019

Advancing R&D

Tech Centers of Excellence

FiltrationChromatography

ProteinsUS and EU

Scaling to Meet Customer Demand

Building our Team

Industry-Leading Talent &

Expertise

18

FiltrationUS

ChromatographyUS, Europe

key manufacturing sites

7

95 External

sales, field applications and service

40Internal

customer service,

marketing

84 North America21 Europe

30 Asia

6%-7% of revenue

Ongoing new product launches

135 (18%)

Our Future is BrightNew Products and Markets Fuel Future Growth

Industry and

Market Trends

19

Increasing capacityflexible facilities

Adoption of single-use

Continuous manufacturingadvances

Greater automationmonitoring and process control

Emerging

Opportunities

New & Future

Products

Gene therapy workflows;Increased investment by industry

TFDF®in fed-batch clarification

Next-generation ligandsfor mAbs and other biologics

Multiplex ATF controllersin perfusion

Flow VPEnext-gen

Our Financial Performance & Guidance

Second Quarter 2020 Financial Highlights

Record Quarterly Revenue

o $87.5M; +19% organic

Strong Gross Margins and Operating Margins

o GM: 57.9% GAAP, 58.2% adjusted

o OM: 22.3% GAAP, 29.2% adjusted

Low Tax Rate

o 1.0% GAAP, 9.1% adjusted (benefits from stock option exercises)

EPS Expansion

o Fully diluted EPS: $0.30 GAAP, $0.42 adjusted (from $0.17 and $0.33 2Q19)

YTD $26.3 operating cash flow, $9.5M Cap Ex investment (capacity, SAP)

21

Second Quarter Business Highlights

GeneTherapy

22

12-point beat on revenue, 75% COVID-related

Strong order book with 40%-50% of order growth COVID-related

Strong margins (GM, OM) reflect sourcing gains, product mix, cost containment

o OPUS column to resin mix, Proteins

Gene Therapy activity continues to accelerate

o Expecting 30%-40% growth compared to 2019

C Technologies commercial team gained traction

o 29% pro forma growth in Q2

o On track for $32M revenue in 2020 despite site visit challenges

Announced acquisition of Engineered Molding Technology

Robust regional growth in both Asia/Pac and Europe

Financial Snapshot

23

* FY 2020 Guidance as of July 30, 2020 earnings call 1. Change in accounting for the treatment of tax on certain intangible amortization was made in 20192. Non-GAAP financial measure; see reconciliation tables in appendix

($s Millions except EPS) 2018 2019 2020 Guidance* Long-Term Goals

Revenue $194.0 $270.2 $332-$340 $500M-$600M by 2023

Revenue Growth37%,

17% organic39%,

33% organic23%-26%,

18%-21% organic10%-15% organic CAGR

Gross Margin (GAAP) 55.4% 55.9% 56.5%-57.0%

Gross Margin (Adj.) 55.8% 57.0% 56.5%-57.0% 60% adj. gross margin

Operating Income (GAAP) $26.0 $36.1 $59-$62

Operating Income (Adj.) $39.4 $63.5 $81-$84 25% adj. operating margin

Net Income (GAAP) $16.6 $21.4 $41-$44

Net Income (Adj.)1 $30.1 $52.5 $66-$69

EPS diluted (GAAP) $0.37 $0.44 $0.77-$0.82

EPS diluted (Adj.)1 $0.66 $1.07 $1.24-$1.29

Cash and Cash Equiv. YE $193.8 $528.4 $560-$570

Fully diluted shares YE (M) 45.5 49.2 53.4

EBITDA (Adj.)2 $45.0 $71.1 $91-$94

Additional 2020 Guidance*

R&D: 6.0%-6.5%

Adj. tax rate: 18%

Cap Ex: $30-$32M

Well Positioned for Sustainable Growth

Four main franchises focused on technology leadership

High impact products for flexible manufacturing; single-use and continuous solutions

Growing total addressable market: ~$3.0B

Expanding manufacturing capacity to stay ahead of increasing demand

R&D engine to launch next-generation products

Strong end market acceleration for biologics, including gene therapies $528.4M

Cash & Equivalents YE 2019

FILTRATION

XCell™ ATFKrosFlo®

TangenX™TFDF™

CHROMATOGRAPHYOPUS®Resins

ELISA Kits

PROTEINSNGL-Impact A®

Protein A Growth Factors

PROCESS ANALYTICSSoloVPE™FlowVPE™

$500M-$600MRevenue Goal

By 2023

24

2525

Thank you!

GAAP to Non-GAAP Reconciliation

27

2019 & 2018 ReconciliationGAAP to Non-GAAP Income from Operations and Net Income

Reconciliation of GAAP Income from Operations to Non-GAAP (Adjusted) Income from Operations(Unaudited, amounts in thousands)

Twelve Months Ended December 31,

2019 2018

GAAP Income from Operations $ 36,083 $ 25,988

Adjustments to Income from Operations

Acquisition and integration costs $ 12,508 $ 2,928

Inventory step-up charges $ 1,483 $ -

Intangible amortization $ 13,441 $ 10,518

Adjusted Income from Operations $ 63,515 $ 39,434

Reconciliation of GAAP Net Income toNon-GAAP (Adjusted) Net Income (Unaudited, amounts in thousands)

Twelve Months Ended December 31,

2019 2018

GAAP Net Income $ 21,411 $ 16,617

Adjustments to Net Income

Acquisition and integration costs $ 13,008 $ 2,928

Inventory step-up charges $ 1,483 $ -

Intangible amortization $ 13,441 $ 10,518

Loss on extinguishment of debt $ 5,650 $ -

Non-cash interest expense $ 7,536 $ 4,248

Tax effect of intangible amortization and acquisition costs $ (10,003) $ (4,204)

Adjusted Net Income $ 52,526 $ 30,107

28

2019 & 2018 ReconciliationGAAP to Non-GAAP Net Income Per Share

Reconciliation of GAAP Net Income per Share to Non-GAAP (Adjusted) Net Income per Share (Unaudited)

Twelve Months Ended December 31,

2019 2018

GAAP Net Income per Share – DILUTED $ 0.44 $ 0.37

Adjustments to Net Income per Share – DILUTED

Acquisition and integration costs $ 0.26 $ 0.06

Inventory step-up charges $ 0.03 $ -

Intangible amortization $ 0.27 $ 0.23

Loss on extinguishment of debt $ 0.11 $ -

Non-cash interest expense $ 0.15 $ 0.09

Tax effect of intangible amortization and acquisition costs $ (0.20) $ (0.09)

Adjusted Net Income per Share – DILUTED $ 1.07 $ 0.66

Totals may not add due to rounding

2019 & 2018 ReconciliationEBITDA to Adjusted EBITDA

Reconciliation of GAAP Net Income to Adjusted EBITDA (Unaudited, amounts in thousands)

Twelve Months Ended December 31,

2019 2018

GAAP Net Income $ 21,411 $ 16,617

Adjustments

Investment Income $ (5,324) $ (1,895)

Interest expense $ 9,292 $ 6,709

Tax Provision $ 4,740 $ 4,819

Depreciation $ 7,317 $ 5,213

Amortization $ 13,551 $ 10,565

EBITDA $ 50,987 $ 42,028

Other Adjustments

Acquisition and integration costs $ 13,008 $ 2,928

Loss on extinguishment of debt $ 5,650 $ -

Inventory step-up charges $ 1,483 $ -

Adjusted EBITDA $ 71,128 $ 44,956

29

2020 Guidance Reconciliation GAAP to Non-GAAP Net Income, Net Income Per Share

Reconciliation ofGAAP Net Income per Share Guidance to Adjusted (Non-GAAP) Net Income per Share Guidance (in thousands)

Twelve Months Ending December 31, 2020

Low End High End

Guidance on Net Income per Share – DILUTED $ 0.77 $ 0.82

Adjustments to Guidance on Net Income per Share – DILUTED

Acquisition and integration costs $ 0.11 $ 0.11

Anticipated pre-tax amortization of acquisition-related intangible assets $ 0.29 $ 0.29

Inventory step-up costs $ 0.00 $ 0.00

Non-cash interest expense $ 0.21 $ 0.21

Tax effect of non-GAAP charges $ (0.15) $ (0.15)

Guidance rounding adjustment $ - $ -

Guidance on Adjusted Net Income per Share – DILUTED

$ 1.24 $ 1.29

Reconciliation ofGAAP Net Income Guidance to Adjusted (Non-GAAP) Net Income Guidance(in thousands)

Twelve Months Ending December 31, 2020

Low End High End

Guidance on Net Income $ 41,000 $ 44,000

Adjustments to Guidance on Net Income

Acquisition and integration costs $ 5,706 $ 5,706

Anticipated pre-tax amortization of acquisition-related intangible assets $ 15,733 $ 15,733

Inventory step-up costs $ 233 $ 233

Non-cash interest expense $ 10,963 $ 10,963

Tax effect of non-GAAP charges $ (7,790) $ (7,790)

Guidance rounding adjustment $ 155 $ 155

Guidance on Adjusted Net Income $ 66,000 $ 69,000

Totals may not add due to rounding

30

Where our Products Fit

in Protein (mAb) and Gene Therapy Workflows

Therapeutic Protein Bioprocessing Workflow

NGL™ Impact A®

XCell™ ATF

KrosFlo® TFF

XCell™ ATF

KrosFlo® TFDF

OPUS® PPC OPUS® PPC

VPE Devices

KrosFlo® TFF

TangenX® TFF

VPE Devices VPE Devices

KrosFlo® TFDF

VPE Devices

32

Gene Therapy Bioprocessing Workflow

OPUS® PPC

OPUS® PP

KrosFlo® TFDF

ProConnex

HF Filters

KrosFlo® TFF

TangenX® TFF

XCell™ ATF

ProConnex

VPE Devices

TangenX® TFF

VPE Devices

HF Filters HF Filters

XCell™ ATFXCell™ ATF

KrosFlo® TFF

OPUS® PPC

VPE Devices

OPUS® PPC

HF Filters

33

Revenue Views

Revenue Splits by Biologic, Customer and Product Type

81%

19%

86%

14%

20192018

35

Biopharma developers

CDMOs

$0

$50

$100

$150

$200

$250

$300

2017 2019

mAbs, rProteins, Vaccines

Gene therapies

~15%

~85%

~96%

~4%

Rev

enu

e ($

Mill

ion

s)

77%

23%

Single-use accounts for 40%+ of total revenue

Consumables and SU

Equipment

2019

*The above charts represent revenue estimates

Revenue Splits by Geography, Commercial/Clinical

36

57%

27%

16%51%

37%

12%

Direct Only(excludes Proteins)

Overall(includes Proteins,

partial year C-Technologies)

North America

Europe

APAC

North America

Europe

APAC

Commercial35%

Clinical65%

Commercial30%

Clinical70%

Overall(includes Proteins)

Direct Only(excludes Proteins)

2019 2019

C Technologies – May 2019 Acquisition

$13.8$14.9

$19.4

$23.7$25.5

$0.0

$5.0

$10.0

$15.0

$20.0

$25.0

$30.0

2015 2016 2017 2018 2019

C Technologies – May 2019 Acquisition

Revolutionizing Protein Concentration Measurement

Strong Revenue Growth, Attractive Margins

Gross margin: Low-to-mid 60%’s

17%

Revenue CAGR 2015-2019

Process Analytics Revenue

Offline and at-lineExpanding the customer base

Quality ControlProcess DevelopmentFormulationManufacturing

~20%service,

consumables

~80%instruments,

software

Novel Slope Spectroscopy® Technology

First and only in-line

We are investing inC Technologies

Direct SalesR&D

38

Solo

VP

E™

Flo

w V

PE™

Rev

en

ue

($M

s)

Adds Process AnalyticsBusiness

• Rapid, accurate protein concentration measurement that eliminates manual sample dilutions

• Flexible, easy to use

Met Repligen’s strictacquisition criteria

Moves up and down in sample

Process Analytics: Solo VPE and Flow VPESlope Spectroscopy®

L

VPE Slope Spectroscopy®plots vary “L” (pathlength) rather

than “c”

Key Process Benefits for Biopharma CustomersVPE Slope Spectroscopy® vs. Traditional UV

Removes or automates multiple steps

• At-line measurement, adaptable to in-line analytics

• Eliminates manual dilution, lowers dilution error

• No sample transfer from PD/manufacturing to labs

Rapid time to results, robustness

• Faster reporting and validation

• Built-in data quality

• Encapsulation improves workflow and validation

Ease of use

• Simple training

VPE

TraditionalUV-Vis

39

Process Analytics: Solo VPE and Flow VPE

Overcoming Issues with Standard UV Spectroscopy

40

4141

Engineered Molding Technology –July 2020 Acquisition

Competitive Landscape

EMT portfolio enables

Repligen to compete more effectively in market for

integrated SU Flow Paths

42

Industry Migration Supports Our Systems Strategy

Industry is migrating to integrated

single-use flow paths and skids for

running critical bioprocessing

unit operations

43

Go-to-Market Strategy

Accelerate

Customer Adoption

Integrate into Repligen Products

& Expand Product Line

Expand OEM:• Strengthen existing relationships with

leading SU vendors for OEM business

• Opportunity to expand beyond core customer base

Go Direct:• Invest in small direct sales force – BSS

• Sell direct to CDMOs and biopharma as part of Repligen single-use offering

Use in Current Products:• Fully integrated flow paths for XCell

ATF®, KrosFlo TFDF®, OPUS®, TangenX

SIUS®, ProConnex®

New Product Offerings: • Leakproof flow paths; high value for

gene therapy, vaccines

• Flow path assemblies for low hold-up volume TFF skids for flat sheet cassettes and hollow fibers

44

How Our Products Work

Filtration: XCell™ ATF

46

Links• How It Works Library• How It Works: Alternating Tangential Flow filtration (ATF)• https://www.repligen.com/applications/perfusion

Filtration: TFDF Benchtop System, SIUS™ Flat Sheet TFF

Links• How It Works Library• How It Works: TFDF™ System for fed-batch clarification• https://www.repligen.com/applications/perfusion

Links• How It Works Library• How It Works: Flat Sheet TFF• https://www.repligen.com/applications/perfusion

47

Filtration: KrosFlo® KR2i TFF System

48

Links• How It Works Library• Technologies: KrosFlo® KR2i TFF System• https://www.repligen.com/applications/perfusion

Chromatography: Inside OPUS 80R

49

Links• How It Works Library• How It Works: Downstream Chromatography• https://www.repligen.com/applications/chromatography• OPUS® 5–80R Pre-packed Columns Technology