Methods employing chromogenic substrates for the photometric determination of prothrombin time have several advantages over conventional coagulometric methods. We evaluated the analytical qualities of two recently introduced reagents for the photometric determination of prothrombin time. The assays were performed on a centrifugal analyser. Both reagents showed good precision, even with sample v...

Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of nosocomial infections that result in extended hospital stays and increased mortality. Therefore, rapid, cost-effective techniques for surveillance and detection of MRSA are critical to the containment and prevention of the spread of MRSA within the health care environment. We examined the ability of 3 chromogenic media (Sp...

A new sensitive and precise method for quantitative determination of direct thrombin inhibitors is described, the ecarin chromogenic assay (ECA). Ecarin is used as the specific prothrombin-activating principle. The cleavage of a chromogenic substrate by meizothrombin is inhibited in a concentration-dependent fashion by direct thrombin inhibitors. For the ECA, the linear measuring range is about...

A colorimetric array for the chromogenic discrimination of organophosphorous derivatives in gas phase has been developed.

Aminoacyl p-nitroaniline (aminoacyl-pNA) and aminoacyl 7-amino-4-methylcoumarin (aminoacyl-AMC) are important synthons for the synthesis of chromogenic/fluorogenic protease substrates. A new efficient method was developed to synthesize aminoacyl-pNA and aminoacyl-AMC derivatives in excellent yields starting from either amino acids or their corresponding commercially available N-hydroxysuccinimi...

The effects of 50 antibiotics on the detection and determination of bacterial endotoxins by the chromogenic method using a Limulus reagent (Tachypleus hemocyte lysate) and a chromogenic substrate of p-nitroaniline derivatives were tested, and the antibiotic concentration for 50% inhibition of the chromogenic reaction in the presence of 0.5 ng of endotoxin (Escherichia coli 0111:B4) per ml was e...

Aim: The aim of this study was to evaluate the influence of temperature on the bleaching efficacy of hydrogen peroxide on chromogenic solutions from wine and tobacco. Methods: Inside optical glass cuvette, equal amounts of chromogenic solution (wine or tobacco), hydrogen peroxide 60% and ultra-pure water were mixed. Initial color readings were performed with a reflectance spectrophotometer imme...

INTRODUCTION Low molecular weight heparins (LMWHs) are used worldwide for the treatment and prophylaxis of thromboembolic disorders. Routine laboratory tests are not required due to the predictable pharmacokinetics of LMWHs, with the exception of pregnant patients, children, patients with renal failure, morbid obesity, or advanced age. Anti-Factor Xa (anti-FXa) plasma levels are most often empl...

A chromogenic chemosensor for selective pyrophosphate sensing in aqueous environments has been developed using silica functionalised surfaces.