Optimal conditions for the storage of German cockroach extract

Abstract

allergen extracts are commonly utilized for diagnosis and immunotherapy; however, the stability of protease-rich extracts is important for a precise diagnosis and treatment efficacy. The present study determines the optimal conditions for the storage of German cockroach allergen extract. Cockroach extracts were reconstituted in four buffers: normal saline (NS), 50% glycerol in NS, 0.3% phenol in NS, or 0.3% phenol and 50% glycerol in NS. The extracts in different buffers were stored either at room temperature (18-26˚C, RT) or refrigerated (2-8˚C). Subsequently, the protein concentration and allergen content (Bla g 1 and Bla g 2) in the extracts were examined for the course of one year. Extract potency was estimated by inhibition ELISA. At least 90.5% protein, 94.4% Bla g 1, 65.2% Bla g 2, and 91.4% potency remained after one year when 50% glycerol nS was added to the extract with refrigeration. However, less than 13.7% protein, 17.1% Bla g 1, 0% Bla g 2 and 32.5% potency were maintained after one year when 50% glycerol nS was not added to the extract and was maintained at RT. The addition of 0.3% phenol NS did not show significant effects on extract stability. The addition of 50% glycerol nS and refrigerated storage temperature were found to be important factors for increasing the shelf life of protease-rich cockroach extract.

Preparation of chemically stable allergen‐specific sublingual immunotherapy from Egyptian allergens

“…Also, according to Jeong et al, 25 the addition of 50% glycerol and refrigerated storage temperature were essential factors for increasing the shelf life of protease-rich cockroach extract.…”

“…The protein content in prepared extracts was adequate from the initial assay to 6 and 9 months later. Also, according to Jeong et al, 25 the addition of 50% glycerol and refrigerated storage temperature were essential factors for increasing the shelf life of protease‐rich cockroach extract.…”

Spatiotemporal proteolytic susceptibility of allergens: positive or negative effects on the allergic sensitization?

“…Stability studies of allergen extracts showed extensive to complete deprivations of Bla g 1/Bla g 2, Amb a 1, Der p 1/Der p 2 (from cockroach, ragweed, house dust mite respectively) when extracts are stored at room temperature or 37 °C ( 7 – 9 ). The addition of protease inhibitors extends the shelf life of P. americana (cockroach) extract, demonstrating that the allergen degradation was protease dependent ( 7 ). It is worth noting that recombinant forms of HDM allergen Der p 5 and Der p 13 can be completely digested by trypsin within an hour ( 10 , 11 ).…”

Comparison of Allergenic Properties among Commercially Available House Dust Mite Allergen Extracts in Korea

“…4 Previous studies have been performed for standardization of extracts for house dust mite (HDM), 5 cockroach, 6 pollens of regional importance, 7 insect venom component allergen (Pac c 3 from Pachycondyla chinensis), 8 and buckwheat. 9 The stabilities of extracts for HDM, 10 cockroach, 11 and pollens 12 have also been studied. Standardization of food allergens, including cereals and various regionally important fish species, is ongoing.…”