SARS-CoV-2 Spike RBD Protein, His Tag (XFG) (MALS verified)

SARS‑CoV‑2 XFG, also known as the “Stratus” variant, is a recombinant Omicron lineage derived from LF.7 and LP.8.1.2, first detected in January 2025 in Southeast Asia2. It carries key spike mutations such as T22N, S31P, K182R, R190S, R346T, K444R, V445R, F456L, N487D, Q493E, and T572I, some linked to enhanced immune evasion. By mid‑2025, XFG spread to over 38 countries, becoming dominant in parts of India and the United States1. Neutralization studies indicate reduced antibody sensitivity compared to earlier Omicron subvariants, prompting its classification by WHO as a Variant Under Monitoring on 25 June 20251.

Product Specifications

Background

Specifications

This protein carries a polyhistidine tag at the C-terminus. The protein has a calculated MW of 26.7 kDa. The protein migrates as 35-40 kDa when calibrated against Star Ribbon Pre-stained Protein Marker under reducing (R) condition (SDS-PAGE) due to glycosylation.

Expression Region

Arg 319 - Lys 537

Target

Spike RBD

Conjugation

Unconjugated

Tag

C-10xHis

Stability

-20°C to -70°C for 12 months in lyophilized state; -70°C for 3 months under sterile conditions after reconstitution. For long term storage, the product should be stored at lyophilized state at -20°C or lower.

Endotoxin

1.0 EU per μg

Purity

90%

Format

Powder

Buffer

PBS, pH7.4

Molecular Weight

26.7 kDa

Additionnal Information

Please see 'Shipping-and-Payments' sheet. Website: https://www.acrobiosystems.com/support/shipping-and-payments

Shipping Conditions

Storage Conditions

-20°C

Package Size

1mg*1

Host or Source

HEK293

Species

SARS-CoV-2

Protein ID

QHD43416.1 (I332V, G339H, R346T, K356T, S371F, S373P, S375F, T376A, R403K, D405N, R408S, K417N, N440K, K444R, V445R, G446S, N450D, L452W, L455S, F456L, N460K, S477N, T478K, N481K, E484K, F486P, N487D, Q493E, Q498R, N501Y, Y505H)