<?xml version="1.0" encoding="utf-8"?>
<!--Generated by DFIN XBRL Instance Document - http://www.dfinsolutions.com/ - Version R3.0 - on 28-April-2025 [10:06:35] {PM}-->
<schema targetNamespace="http://ad.com/20241231" elementFormDefault="qualified" xmlns:adpt="http://ad.com/20241231" xmlns="http://www.w3.org/2001/XMLSchema" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xl="http://www.xbrl.org/2003/XLink" xmlns:us-gaap="http://fasb.org/us-gaap/2024" xmlns:country="http://xbrl.sec.gov/country/2024" xmlns:dei="http://xbrl.sec.gov/dei/2024" xmlns:us-types="http://fasb.org/us-types/2024" xmlns:deprecated="http://www.xbrl.org/2009/arcrole/fact-explanatoryFact" xmlns:srt="http://fasb.org/srt/2024" xmlns:srt-types="http://fasb.org/srt-types/2024" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2020-01-21" xmlns:ecd="http://xbrl.sec.gov/ecd/2024">
<annotation>
<appinfo />
</annotation>
<import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd" />
<import namespace="http://www.xbrl.org/2003/linkbase" schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" />
<import namespace="http://xbrl.sec.gov/dei/2024" schemaLocation="https://xbrl.sec.gov/dei/2024/dei-2024.xsd" />
<import namespace="http://xbrl.sec.gov/dei-sub/2024" schemaLocation="https://xbrl.sec.gov/dei/2024/dei-sub-2024.xsd" />
<import namespace="http://www.xbrl.org/dtr/type/2020-01-21" schemaLocation="https://www.xbrl.org/dtr/type/2020-01-21/types.xsd" />
<import namespace="http://fasb.org/srt/2024" schemaLocation="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd" />
<import namespace="http://fasb.org/srt-types/2024" schemaLocation="https://xbrl.fasb.org/srt/2024/elts/srt-types-2024.xsd" />
<import namespace="http://xbrl.sec.gov/ecd-sub/2024" schemaLocation="https://xbrl.sec.gov/ecd/2024/ecd-sub-2024.xsd" />
<import namespace="http://xbrl.sec.gov/ecd/2024" schemaLocation="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd" />
<import namespace="http://www.xbrl.org/2006/ref" schemaLocation="http://www.xbrl.org/2006/ref-2006-02-27.xsd" />
<import namespace="http://xbrl.org/2005/xbrldt" schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd" />
<import namespace="http://fasb.org/srt-roles/2024" schemaLocation="https://xbrl.fasb.org/srt/2024/elts/srt-roles-2024.xsd" />
</schema>
