Quest Diagnostics is a trusted healthcare provider offering a range of diagnostic services, including COVID-19 antibody testing, drug screening, and routine lab tests. The company has a presence across various locations, with the Riverside facility being a popular choice among customers. The Riverside location is known for its cleanliness, knowledgeable staff, and efficient service. Customers particularly appreciate the professionalism and friendly demeanor of the phlebotomists, such as Liz, who consistently provide a positive experience. While the online appointment system and kiosk-based check-in process make the overall experience convenient, the company could consider improving accessibility for older patients and non-English speakers. Suggestions include adding hooks or a simple table in the restrooms to accommodate personal belongings and assigning a receptionist in the waiting room to assist those who may need additional support. Overall, Quest Diagnostics in Riverside is praised for its reliable services, clean facilities, and courteous staff, making it a preferred choice for many customers in the area.