How to extract a alphanumeric values with special characters

[av_]

I want to extract Sample ID field value
"Sample ID":"020ab888-a7ce-4e25-z8h8-a658bf21ech9"

[yuanliu]

Additionally, the format looks too much like part of JSON.  If part or the whole of your event is JSON, you should treat it as structured data, not isolated strings.  Can you share the raw event? (Anonymize as needed.)

[richgalloway]

What you need is everything between the quotation marks.  Try this

| rex "Sample ID\\\":\\\"(?<SampleID>[^\"]+)"