Isolated genetics explained: what "iso" means on a spore syringe

01Multispore first

A spore print carries millions of spores, and they are not identical. A print is the product of a fruiting body that itself came from the meeting of many genetic combinations, so a "multispore" syringe is a broad population: the strain in outline, with variation inside it. Under the microscope that shows up as a wider spread of spore size and, on the record sheet, as more scatter.

02What isolation does

To isolate, a geneticist takes the line down to a single studied phenotype and works it until it is stable and repeatable, then takes prints from that stabilised line. The spores in the resulting syringe still vary a little, as all sexual spores do, but they descend from one selected phenotype rather than the whole spread. The label usually says "iso", "isolated" or "isolate", and a serious listing names who did the work and what they selected for.

MycoWorld marks these lines with an ISO tag and credits the geneticist on the card, because an isolate is somebody's work as much as it is a specimen.

03Why it matters for microscopy

• Consistency. A syringe from an isolate gives the same population next month as it did this month. Your reference series stays comparable.
• Tighter measurements. Spore size clusters more closely, which makes real differences between lines easier to see.
• A meaningful name. "Jack Frost iso" means a specific, worked phenotype, not just a print from something called Jack Frost.
• Provenance. Isolates come with a story: who made them, from what, and when.

04Why isolates cost more

Time. An isolate represents weeks of selection and stabilisation before a single print is taken, plus the record-keeping that makes the name trustworthy. That is why an isolated syringe in the library sits around £20 while multispore lines and older classics can be less. For side-by-side comparison work, the isolate is the better spend.

05Reading the rest of the label

Alongside ISO you will see the species, the format (syringe, print or swab), the collection it belongs to and, for a cross, the two parents. Our guide to reading a strain name decodes the rest, and the lineage explorer shows how the isolates in the library relate to each other.