Abstract: A chemiluminescent substrate of a hydrolytic enzyme having the following general Formula I is disclosed, as follows: Lumi-M-PFormula I where “Lumi” is a chemiluminescent moiety capable of producing light (a) by itself, (b) with MP attached and (c) with M attached. Examples of Lumi include chemiluminescent acridinium compounds, benzacridinium compounds, quinolinium compounds, isoquinolinium compounds, phenanthridinium compounds, and lucigenin compounds, spiroacridan compounds, luminol compounds and isoluminol compounds. M is a multivalent heteroatom having at least one lone pair of electrons selected from oxygen, nitrogen and sulfur, directly attached to the light emitting moiety of Lumi at one end and to P at the other end. P is a group that can be readily removed by hydrolytic enzymes. An enzymatic reaction utilizing the above compound is the following: where HE is a hydrolytic enzyme. Lumi-M is a chemiluminescent product having physical and/or chemical properties different from those of Lumi-M-P.

Abstract: The method of diluting a fluid sample for analysis in a sample analysis system includes the provision of an aspiration probe with two interior sections. The first interior section of the probe has a first diameter and is proximate the aspiration opening of the probe. The second interior section of the probe has a second diameter of greater magnitude than the first diameter and is located distally of the first section. The probe aspirates in consecutive order selected amounts of fluid sample and diluent into the first interior section of the probe. The fluid sample and diluent are mixed in the second interior section of the probe by moving the sample and diluent back and forth in the second interior section a predetermined number of times. The back and forth movement of diluent and fluid sample in the second interior section of the probe provides substantially uniform mixing of the sample and diluent. The use of a Teflon.RTM.