Y-PER is a detergent cell extracts from S. cerevisiae. It can be an advantage for cell extracts preparation from yeast compared to glass beads as less foam is produced.

he manufacturer has a page about the product here.

Cost of the reagent is about 25 cents per extraction, however the Y-PER reagent is most likely 10 mg/mL SB3-14 (myristyl sulfobetaine).

See this page for more information and this patent.

The detergent is sold commercially.

Sigma charges about 100 Euro for 5g of SB3-14 (T7763-5G) which can make one liter homemade Y-PER, cutting costs to about half.

Se this list at BitesizeBio for alternative commercial products.