Provided is a diagnostic kit for determining infection with Methicillin-Resistant Staphylococcus aureus (MRSA) in a specimen, and a method for determining the infection with MRSA using the diagnostic kit is performed by visually observing a color change after LAMP reaction, and the color change is caused by a change in a magnesium concentration and confirmed using a specific dye compound which sensitively reacts with magnesium ions. The amplification of the MRSA DNA is performed using the loop-mediated isothermal amplification (LAMP), so that the diagnostic kit has advantages of being conveniently used anytime and anywhere and quickly diagnosing.

An ink set includes a pigment ink, containing a pigment, and a dye ink containing the compound represented by formula (y-1) below or a salt thereof. ##STR00001##

Provided is a diagnostic kit for determining infection with Methicillin-Resistant Staphylococcus aureus (MRSA) in a specimen, and a method for determining the infection with MRSA using the diagnostic kit is performed by visually observing a color change after LAMP reaction, and the color change is caused by a change in a magnesium concentration and confirmed using a specific dye compound which sensitively reacts with magnesium ions. The amplification of the MRSA DNA is performed using the loop-mediated isothermal amplification (LAMP), so that the diagnostic kit has advantages of being conveniently used anytime and anywhere and quickly diagnosing.

An ink set includes a pigment ink, containing a pigment, and a dye ink containing the compound represented by formula (y-1) below or a salt thereof.

##STR00001##

Provided are a coloring composition including a compound represented by Formula (1) shown in this specification and a compound represented by Formula (D) shown in this specification, an ink jet recording ink including the coloring composition, an ink jet recording method using the ink jet recording ink, and an ink jet printer cartridge that is filled with the ink jet recording ink.

The present invention refers to dyes of the formula (I) and mixtures thereof ##STR00001##
a process for their production and to their use.