Colorimetric COVID-19 Rapid-Test and Methods of Using Same

A method of testing a subject for COVID-19, the method comprising:

• obtaining a saliva sample from the subject;
• diluting the saliva sample with a dilution buffer comprising a base;
• contacting the diluted saliva sample with loop-mediated isothermal amplification (LAMP) primers that bind the N gene of the SARS-CoV-2 virus to form a test mixture under conditions that allow for reverse-transcription LAMP (RT-LAMP) of RNA material within the diluted saliva sample to take place;
• wherein the LAMP primer comprises an inner primer,
• wherein the reverse-transcribed RNA material comprises a first region which 5′ end is conjugated to the 3′ end of a second region which 5′ end is conjugated to the 3′ end of a DNA segment which is amplified by RT-LAMP;
• wherein the 3′ end of inner primer comprises a first sequence that is complementary to the first region, and the first sequence is conjugated through its 5′ end to the 3′ end of a second sequence that is identical to the second region;
• wherein a (A)n polynucleotide, wherein n is 2, 3, 4, 5, 6, 7, 8, 9, or 10, is inserted between the first and second sequences within the inner primer;
• and
• analyzing the color of the test mixture.